diff --git a/logic/languages/jetbrains.mps.logic/generator/template/main@generator.mps b/logic/languages/jetbrains.mps.logic/generator/template/main@generator.mps
index 1fbeed72..4783441d 100644
--- a/logic/languages/jetbrains.mps.logic/generator/template/main@generator.mps
+++ b/logic/languages/jetbrains.mps.logic/generator/template/main@generator.mps
@@ -24,7 +24,6 @@
     <import index="wyt6" ref="6354ebe7-c22a-4a0f-ac54-50b52ab9b065/java:java.lang(JDK/)" />
     <import index="nz6g" ref="r:ac00f724-30be-446e-805c-2345efc460d7(jetbrains.mps.lang.typesystem2.program)" />
     <import index="tpck" ref="r:00000000-0000-4000-0000-011c89590288(jetbrains.mps.lang.core.structure)" implicit="true" />
-    <import index="ha02" ref="r:09e53496-6477-45e7-abd5-eaf3fac3b360(jetbrains.mps.logic.behavior)" implicit="true" />
   </imports>
   <registry>
     <language id="f3061a53-9226-4cc5-a443-f952ceaf5816" name="jetbrains.mps.baseLanguage">
@@ -284,7 +283,6 @@
       <concept id="1803469493727536395" name="jetbrains.mps.lang.smodel.structure.OperationParm_StopConceptList" flags="ng" index="hTh3S">
         <child id="1803469493727536396" name="concept" index="hTh3Z" />
       </concept>
-      <concept id="1179409122411" name="jetbrains.mps.lang.smodel.structure.Node_ConceptMethodCall" flags="nn" index="2qgKlT" />
       <concept id="1145404486709" name="jetbrains.mps.lang.smodel.structure.SemanticDowncastExpression" flags="nn" index="2JrnkZ">
         <child id="1145404616321" name="leftExpression" index="2JrQYb" />
       </concept>
@@ -506,7 +504,7 @@
               <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
               <node concept="2YIFZM" id="7nPD14NONtQ" role="37wK5m">
                 <ref role="37wK5l" to="nz6g:7nPD14NOHGU" resolve="wildcardMetaLogical" />
-                <ref role="1Pybhc" to="nz6g:7nPD14NOCSa" resolve="MetaLogicalFactory" />
+                <ref role="1Pybhc" to="nz6g:7nPD14NOCSa" resolve="ProgramFactory" />
                 <node concept="3VsKOn" id="7nPD14NONvH" role="37wK5m">
                   <ref role="3VsUkX" to="wyt6:~String" resolve="String" />
                 </node>
@@ -520,7 +518,7 @@
             <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
             <node concept="2YIFZM" id="7nPD14NONnQ" role="37wK5m">
               <ref role="37wK5l" to="nz6g:7nPD14NOHGU" resolve="wildcardMetaLogical" />
-              <ref role="1Pybhc" to="nz6g:7nPD14NOCSa" resolve="MetaLogicalFactory" />
+              <ref role="1Pybhc" to="nz6g:7nPD14NOCSa" resolve="ProgramFactory" />
               <node concept="3VsKOn" id="7nPD14NONpR" role="37wK5m">
                 <ref role="3VsUkX" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
               </node>
@@ -1579,8 +1577,8 @@
                 <node concept="1Yb3XT" id="514BAS_YAHo" role="1Ub_4A">
                   <property role="TrG5h" value="dummy" />
                   <node concept="2DMOqp" id="514BAS_YAHp" role="1YbcFS">
-                    <node concept="3uibUv" id="514BAS_YBB4" role="2DMOqq">
-                      <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
+                    <node concept="3uibUv" id="3mz2_dYrgHu" role="2DMOqq">
+                      <ref role="3uigEE" to="45ys:1mP5b6jQP$C" resolve="Logical" />
                     </node>
                   </node>
                 </node>
@@ -1595,43 +1593,19 @@
           <node concept="3cpWs8" id="514BAS_YBDu" role="3cqZAp">
             <node concept="3cpWsn" id="514BAS_YBDv" role="3cpWs9">
               <property role="TrG5h" value="logical" />
-              <node concept="3uibUv" id="514BAS_YBGL" role="1tU5fm">
-                <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
+              <node concept="3uibUv" id="3mz2_dYuqQi" role="1tU5fm">
+                <ref role="3uigEE" to="45ys:1mP5b6jQP$C" resolve="Logical" />
               </node>
             </node>
           </node>
           <node concept="3clFbF" id="514BAS_YBDx" role="3cqZAp">
             <node concept="2YIFZM" id="514BAS_YBDy" role="3clFbG">
               <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
-              <ref role="37wK5l" to="yg8f:7FFmDVAK9bb" resolve="asAtom" />
+              <ref role="37wK5l" to="yg8f:4TCblo5YI1H" resolve="asAtom" />
               <node concept="37vLTw" id="514BAS_YBDz" role="37wK5m">
                 <ref role="3cqZAo" node="514BAS_YBDv" resolve="logical" />
                 <node concept="29HgVG" id="514BAS_YBD$" role="lGtFl" />
               </node>
-              <node concept="3VsKOn" id="7FFmDVAKa2E" role="37wK5m">
-                <ref role="3VsUkX" to="ie8e:5JQSuNswOXL" resolve="StemFunc" />
-                <node concept="1ZhdrF" id="7FFmDVALaiM" role="lGtFl">
-                  <property role="P3scX" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1116615150612/1116615189566" />
-                  <property role="2qtEX8" value="classifier" />
-                  <node concept="3$xsQk" id="7FFmDVALaiN" role="3$ytzL">
-                    <node concept="3clFbS" id="7FFmDVALaiO" role="2VODD2">
-                      <node concept="3clFbF" id="7FFmDVALer8" role="3cqZAp">
-                        <node concept="2OqwBi" id="7FFmDVALexa" role="3clFbG">
-                          <node concept="2OqwBi" id="7FFmDVALesF" role="2Oq$k0">
-                            <node concept="1iwH7S" id="7FFmDVALer7" role="2Oq$k0" />
-                            <node concept="3cR$yn" id="7FFmDVALeu1" role="2OqNvi">
-                              <ref role="3cRzXn" node="7FFmDVALe4e" resolve="atom" />
-                            </node>
-                          </node>
-                          <node concept="2qgKlT" id="7FFmDVALe$J" role="2OqNvi">
-                            <ref role="37wK5l" to="ha02:7FFmDVAL6VY" resolve="runtimeType" />
-                          </node>
-                        </node>
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
               <node concept="raruj" id="514BAS_YBD_" role="lGtFl" />
             </node>
           </node>
diff --git a/logic/languages/jetbrains.mps.logic/languageModels/typesystem.mps b/logic/languages/jetbrains.mps.logic/languageModels/typesystem.mps
index 6509cbbb..4c407323 100644
--- a/logic/languages/jetbrains.mps.logic/languageModels/typesystem.mps
+++ b/logic/languages/jetbrains.mps.logic/languageModels/typesystem.mps
@@ -527,7 +527,7 @@
                     </node>
                     <node concept="2c44tf" id="6MYr6Jy87W1" role="3JuZjQ">
                       <node concept="3uibUv" id="6MYr6Jy87W2" role="2c44tc">
-                        <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
+                        <ref role="3uigEE" to="45ys:1mP5b6jQP$C" resolve="Logical" />
                         <node concept="3uibUv" id="6MYr6Jy87W3" role="11_B2D">
                           <ref role="3uigEE" to="wyt6:~String" resolve="String" />
                         </node>
diff --git a/logic/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin.mps b/logic/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin.mps
index 88d8f98c..8f5cd4d4 100644
--- a/logic/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin.mps
+++ b/logic/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin.mps
@@ -17,7 +17,6 @@
     <import index="rchb" ref="r:f43ee4a0-488a-425a-87a0-594ab3b0d15f(jetbrains.mps.logic.reactor.program)" />
     <import index="omn0" ref="r:4e44cb56-a834-45de-a0c4-c49a5c86e78e(jetbrains.mps.logic.builtin.solver)" />
     <import index="yt73" ref="7526e0cf-1ce7-46f8-a555-9eca1e06c23b/java:jetbrains.mps.unification(jetbrains.mps.unification.tree/)" />
-    <import index="nz6g" ref="r:ac00f724-30be-446e-805c-2345efc460d7(jetbrains.mps.lang.typesystem2.program)" />
   </imports>
   <registry>
     <language id="f3061a53-9226-4cc5-a443-f952ceaf5816" name="jetbrains.mps.baseLanguage">
@@ -173,9 +172,6 @@
         <child id="5375687026011219971" name="member" index="jymVt" unordered="true" />
       </concept>
       <concept id="1171903607971" name="jetbrains.mps.baseLanguage.structure.WildCardType" flags="in" index="3qTvmN" />
-      <concept id="1171903916106" name="jetbrains.mps.baseLanguage.structure.UpperBoundType" flags="in" index="3qUE_q">
-        <child id="1171903916107" name="bound" index="3qUE_r" />
-      </concept>
       <concept id="7812454656619025416" name="jetbrains.mps.baseLanguage.structure.MethodDeclaration" flags="ng" index="1rXfSm">
         <property id="8355037393041754995" name="isNative" index="2aFKle" />
       </concept>
@@ -213,12 +209,6 @@
         <child id="1107797138135" name="extendedInterface" index="3HQHJm" />
       </concept>
       <concept id="1208890769693" name="jetbrains.mps.baseLanguage.structure.ArrayLengthOperation" flags="nn" index="1Rwk04" />
-      <concept id="6329021646629104957" name="jetbrains.mps.baseLanguage.structure.TextCommentPart" flags="nn" index="3SKdUq">
-        <property id="6329021646629104958" name="text" index="3SKdUp" />
-      </concept>
-      <concept id="6329021646629104954" name="jetbrains.mps.baseLanguage.structure.SingleLineComment" flags="nn" index="3SKdUt">
-        <child id="6329021646629175155" name="commentPart" index="3SKWNk" />
-      </concept>
       <concept id="1146644602865" name="jetbrains.mps.baseLanguage.structure.PublicVisibility" flags="nn" index="3Tm1VV" />
       <concept id="1146644623116" name="jetbrains.mps.baseLanguage.structure.PrivateVisibility" flags="nn" index="3Tm6S6" />
       <concept id="1146644641414" name="jetbrains.mps.baseLanguage.structure.ProtectedVisibility" flags="nn" index="3Tmbuc" />
@@ -234,190 +224,7 @@
   </registry>
   <node concept="312cEu" id="677NV565N1x">
     <property role="TrG5h" value="LogicalUtil" />
-    <node concept="2tJIrI" id="677NV565N1L" role="jymVt" />
-    <node concept="2YIFZL" id="677NV565VC2" role="jymVt">
-      <property role="TrG5h" value="asAtomArray" />
-      <node concept="37vLTG" id="677NV565VMW" role="3clF46">
-        <property role="TrG5h" value="logicalArr" />
-        <node concept="8X2XB" id="677NV565VO6" role="1tU5fm">
-          <node concept="3uibUv" id="qubcdt7lYi" role="8Xvag">
-            <ref role="3uigEE" node="qubcdt1pkm" resolve="LogicalExt" />
-          </node>
-        </node>
-      </node>
-      <node concept="10Q1$e" id="677NV565VLO" role="3clF45">
-        <node concept="3uibUv" id="677NV565VLD" role="10Q1$1">
-          <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-        </node>
-      </node>
-      <node concept="3Tm1VV" id="677NV565VC5" role="1B3o_S" />
-      <node concept="3clFbS" id="677NV565VC6" role="3clF47">
-        <node concept="3cpWs8" id="677NV565Z2M" role="3cqZAp">
-          <node concept="3cpWsn" id="677NV565Z2N" role="3cpWs9">
-            <property role="TrG5h" value="array" />
-            <node concept="10Q1$e" id="677NV565Z2E" role="1tU5fm">
-              <node concept="3uibUv" id="677NV565Z2H" role="10Q1$1">
-                <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-              </node>
-            </node>
-            <node concept="2ShNRf" id="677NV565Z2O" role="33vP2m">
-              <node concept="3$_iS1" id="677NV565Z2P" role="2ShVmc">
-                <node concept="3$GHV9" id="677NV565Z2Q" role="3$GQph">
-                  <node concept="2OqwBi" id="677NV565ZG1" role="3$I4v7">
-                    <node concept="37vLTw" id="677NV565ZcD" role="2Oq$k0">
-                      <ref role="3cqZAo" node="677NV565VMW" resolve="logicalArr" />
-                    </node>
-                    <node concept="1Rwk04" id="677NV5660Jm" role="2OqNvi" />
-                  </node>
-                </node>
-                <node concept="3uibUv" id="677NV565Z2R" role="3$_nBY">
-                  <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="1Dw8fO" id="677NV5660P6" role="3cqZAp">
-          <node concept="3clFbS" id="677NV5660P8" role="2LFqv$">
-            <node concept="3clFbF" id="677NV566355" role="3cqZAp">
-              <node concept="37vLTI" id="677NV5663dk" role="3clFbG">
-                <node concept="2OqwBi" id="677NV5664S0" role="37vLTx">
-                  <node concept="2OqwBi" id="677NV56641N" role="2Oq$k0">
-                    <node concept="AH0OO" id="677NV5663zs" role="2Oq$k0">
-                      <node concept="37vLTw" id="677NV5663K_" role="AHEQo">
-                        <ref role="3cqZAo" node="677NV5660P9" resolve="i" />
-                      </node>
-                      <node concept="37vLTw" id="677NV5663ha" role="AHHXb">
-                        <ref role="3cqZAo" node="677NV565VMW" resolve="logicalArr" />
-                      </node>
-                    </node>
-                    <node concept="liA8E" id="677NV5664Mj" role="2OqNvi">
-                      <ref role="37wK5l" node="7jC45Kci98e" resolve="asAtom" />
-                    </node>
-                  </node>
-                  <node concept="liA8E" id="677NV5665A4" role="2OqNvi">
-                    <ref role="37wK5l" to="ie8e:2QE4RCGndD7" resolve="asRoot" />
-                  </node>
-                </node>
-                <node concept="AH0OO" id="677NV56636O" role="37vLTJ">
-                  <node concept="37vLTw" id="677NV56639b" role="AHEQo">
-                    <ref role="3cqZAo" node="677NV5660P9" resolve="i" />
-                  </node>
-                  <node concept="37vLTw" id="677NV566353" role="AHHXb">
-                    <ref role="3cqZAo" node="677NV565Z2N" resolve="array" />
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-          <node concept="3cpWsn" id="677NV5660P9" role="1Duv9x">
-            <property role="TrG5h" value="i" />
-            <node concept="10Oyi0" id="677NV5660QJ" role="1tU5fm" />
-            <node concept="3cmrfG" id="677NV5660T9" role="33vP2m">
-              <property role="3cmrfH" value="0" />
-            </node>
-          </node>
-          <node concept="3eOVzh" id="677NV56j4xv" role="1Dwp0S">
-            <node concept="37vLTw" id="677NV5660Uc" role="3uHU7B">
-              <ref role="3cqZAo" node="677NV5660P9" resolve="i" />
-            </node>
-            <node concept="2OqwBi" id="677NV5661$p" role="3uHU7w">
-              <node concept="37vLTw" id="677NV5661mM" role="2Oq$k0">
-                <ref role="3cqZAo" node="677NV565VMW" resolve="logicalArr" />
-              </node>
-              <node concept="1Rwk04" id="677NV5662Ak" role="2OqNvi" />
-            </node>
-          </node>
-          <node concept="3uNrnE" id="677NV5662VZ" role="1Dwrff">
-            <node concept="37vLTw" id="677NV5662W1" role="2$L3a6">
-              <ref role="3cqZAo" node="677NV5660P9" resolve="i" />
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbF" id="677NV565X25" role="3cqZAp">
-          <node concept="37vLTw" id="677NV565Z2S" role="3clFbG">
-            <ref role="3cqZAo" node="677NV565Z2N" resolve="array" />
-          </node>
-        </node>
-      </node>
-    </node>
-    <node concept="2tJIrI" id="514BAS_YB7x" role="jymVt" />
-    <node concept="2YIFZL" id="514BAS_YAUt" role="jymVt">
-      <property role="TrG5h" value="asAtom" />
-      <node concept="37vLTG" id="514BAS_YAUu" role="3clF46">
-        <property role="TrG5h" value="logical" />
-        <node concept="3uibUv" id="514BAS_YBf7" role="1tU5fm">
-          <ref role="3uigEE" node="qubcdt1pkm" resolve="LogicalExt" />
-        </node>
-      </node>
-      <node concept="3uibUv" id="514BAS_YAUw" role="3clF45">
-        <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-      </node>
-      <node concept="3Tm1VV" id="514BAS_YAUx" role="1B3o_S" />
-      <node concept="3clFbS" id="514BAS_YAUy" role="3clF47">
-        <node concept="3SKdUt" id="4TCblo5Prob" role="3cqZAp">
-          <node concept="3SKdUq" id="4TCblo5Prod" role="3SKWNk">
-            <property role="3SKdUp" value="FIXME use LogicalAtom" />
-          </node>
-        </node>
-        <node concept="3clFbF" id="514BAS_YBiz" role="3cqZAp">
-          <node concept="2OqwBi" id="514BAS_YBk4" role="3clFbG">
-            <node concept="37vLTw" id="514BAS_YBiy" role="2Oq$k0">
-              <ref role="3cqZAo" node="514BAS_YAUu" resolve="logical" />
-            </node>
-            <node concept="liA8E" id="514BAS_YBoG" role="2OqNvi">
-              <ref role="37wK5l" node="7jC45Kci98e" resolve="asAtom" />
-            </node>
-          </node>
-        </node>
-      </node>
-    </node>
     <node concept="2tJIrI" id="7HUwyZb7alE" role="jymVt" />
-    <node concept="2YIFZL" id="7FFmDVAK9bb" role="jymVt">
-      <property role="TrG5h" value="asAtom" />
-      <node concept="37vLTG" id="7FFmDVAK9bc" role="3clF46">
-        <property role="TrG5h" value="logical" />
-        <node concept="3uibUv" id="7FFmDVAK9bd" role="1tU5fm">
-          <ref role="3uigEE" node="qubcdt1pkm" resolve="LogicalExt" />
-        </node>
-      </node>
-      <node concept="37vLTG" id="7FFmDVAK9e4" role="3clF46">
-        <property role="TrG5h" value="prototype" />
-        <node concept="3uibUv" id="7FFmDVAK9Ej" role="1tU5fm">
-          <ref role="3uigEE" to="wyt6:~Class" resolve="Class" />
-          <node concept="3qUE_q" id="7FFmDVAK9Kv" role="11_B2D">
-            <node concept="3uibUv" id="7FFmDVAK9Mu" role="3qUE_r">
-              <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="3uibUv" id="7FFmDVAK9be" role="3clF45">
-        <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-      </node>
-      <node concept="3Tm1VV" id="7FFmDVAK9bf" role="1B3o_S" />
-      <node concept="3clFbS" id="7FFmDVAK9bg" role="3clF47">
-        <node concept="3SKdUt" id="4TCblo5Pro_" role="3cqZAp">
-          <node concept="3SKdUq" id="4TCblo5ProA" role="3SKWNk">
-            <property role="3SKdUp" value="FIXME use LogicalAtom" />
-          </node>
-        </node>
-        <node concept="3clFbF" id="7FFmDVAK9bh" role="3cqZAp">
-          <node concept="2OqwBi" id="7FFmDVAK9bi" role="3clFbG">
-            <node concept="37vLTw" id="7FFmDVAK9bj" role="2Oq$k0">
-              <ref role="3cqZAo" node="7FFmDVAK9bc" resolve="logical" />
-            </node>
-            <node concept="liA8E" id="7FFmDVAK9bk" role="2OqNvi">
-              <ref role="37wK5l" node="7MlQDeOy9SE" resolve="asAtom" />
-              <node concept="37vLTw" id="7FFmDVAK9R_" role="37wK5m">
-                <ref role="3cqZAo" node="7FFmDVAK9e4" resolve="prototype" />
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-    </node>
-    <node concept="2tJIrI" id="7FFmDVAK9ba" role="jymVt" />
     <node concept="2YIFZL" id="7HUwyZb7b7C" role="jymVt">
       <property role="TrG5h" value="asAtomArray" />
       <node concept="37vLTG" id="7HUwyZb7b7D" role="3clF46">
@@ -833,83 +640,6 @@
     </node>
     <node concept="3Tm1VV" id="5_6ImQZ8j9E" role="1B3o_S" />
   </node>
-  <node concept="3HP615" id="qubcdt1pkm">
-    <property role="TrG5h" value="LogicalExt" />
-    <node concept="2tJIrI" id="qubcdt7pFV" role="jymVt" />
-    <node concept="3clFb_" id="dfChU1eNVy" role="jymVt">
-      <property role="1EzhhJ" value="true" />
-      <property role="TrG5h" value="findRoot" />
-      <node concept="3uibUv" id="dfChU1eNWP" role="3clF45">
-        <ref role="3uigEE" node="qubcdt1pkm" resolve="LogicalExt" />
-        <node concept="16syzq" id="dfChU1eNXI" role="11_B2D">
-          <ref role="16sUi3" node="qubcdt52KU" resolve="T" />
-        </node>
-      </node>
-      <node concept="3Tm1VV" id="dfChU1eNV_" role="1B3o_S" />
-      <node concept="3clFbS" id="dfChU1eNVA" role="3clF47" />
-    </node>
-    <node concept="2tJIrI" id="qubcdt7pGl" role="jymVt" />
-    <node concept="3clFb_" id="7jC45Kci98e" role="jymVt">
-      <property role="1EzhhJ" value="true" />
-      <property role="TrG5h" value="asAtom" />
-      <node concept="3uibUv" id="7jC45Kci98f" role="3clF45">
-        <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-      </node>
-      <node concept="3Tm1VV" id="7jC45Kci98h" role="1B3o_S" />
-      <node concept="3clFbS" id="7jC45Kci98i" role="3clF47" />
-    </node>
-    <node concept="2tJIrI" id="7MlQDeOyaKI" role="jymVt" />
-    <node concept="3clFb_" id="7MlQDeOy9SE" role="jymVt">
-      <property role="1EzhhJ" value="true" />
-      <property role="TrG5h" value="asAtom" />
-      <node concept="3uibUv" id="7MlQDeOy9SF" role="3clF45">
-        <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-      </node>
-      <node concept="3Tm1VV" id="7MlQDeOy9SG" role="1B3o_S" />
-      <node concept="3clFbS" id="7MlQDeOy9SH" role="3clF47" />
-      <node concept="37vLTG" id="7MlQDeOybAm" role="3clF46">
-        <property role="TrG5h" value="prototype" />
-        <node concept="3uibUv" id="7MlQDeOybAl" role="1tU5fm">
-          <ref role="3uigEE" to="wyt6:~Class" resolve="Class" />
-          <node concept="3qUE_q" id="7MlQDeOybG7" role="11_B2D">
-            <node concept="3uibUv" id="7MlQDeOybIO" role="3qUE_r">
-              <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-            </node>
-          </node>
-        </node>
-      </node>
-    </node>
-    <node concept="2tJIrI" id="5zfvpQ7aL7l" role="jymVt" />
-    <node concept="3clFb_" id="6Sag3Ksvh9N" role="jymVt">
-      <property role="1EzhhJ" value="true" />
-      <property role="TrG5h" value="isValid" />
-      <node concept="37vLTG" id="6Sag3Ksvngn" role="3clF46">
-        <property role="TrG5h" value="prototype" />
-        <node concept="3uibUv" id="6Sag3KsvnoC" role="1tU5fm">
-          <ref role="3uigEE" to="wyt6:~Class" resolve="Class" />
-          <node concept="3qUE_q" id="6Sag3KsvnJK" role="11_B2D">
-            <node concept="3uibUv" id="6Sag3KsvnR$" role="3qUE_r">
-              <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="10P_77" id="6Sag3KsvhiY" role="3clF45" />
-      <node concept="3Tm1VV" id="6Sag3Ksvh9Q" role="1B3o_S" />
-      <node concept="3clFbS" id="6Sag3Ksvh9R" role="3clF47" />
-    </node>
-    <node concept="2tJIrI" id="6Sag3Ksvh8c" role="jymVt" />
-    <node concept="3Tm1VV" id="qubcdt1pkn" role="1B3o_S" />
-    <node concept="3uibUv" id="qubcdt1pkF" role="3HQHJm">
-      <ref role="3uigEE" to="45ys:1mP5b6jQP$C" resolve="Logical" />
-      <node concept="16syzq" id="qubcdt52Lk" role="11_B2D">
-        <ref role="16sUi3" node="qubcdt52KU" resolve="T" />
-      </node>
-    </node>
-    <node concept="16euLQ" id="qubcdt52KU" role="16eVyc">
-      <property role="TrG5h" value="T" />
-    </node>
-  </node>
   <node concept="3HP615" id="qubcdtxBiR">
     <property role="TrG5h" value="EvaluationTraceExt" />
     <node concept="2tJIrI" id="qubcdtxBuI" role="jymVt" />
diff --git a/logic/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin/unification.mps b/logic/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin/unification.mps
index b7d5764e..a85e7262 100644
--- a/logic/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin/unification.mps
+++ b/logic/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin/unification.mps
@@ -50,9 +50,7 @@
       <concept id="1145552977093" name="jetbrains.mps.baseLanguage.structure.GenericNewExpression" flags="nn" index="2ShNRf">
         <child id="1145553007750" name="creator" index="2ShVmc" />
       </concept>
-      <concept id="1070475354124" name="jetbrains.mps.baseLanguage.structure.ThisExpression" flags="nn" index="Xjq3P">
-        <reference id="1182955020723" name="classConcept" index="1HBi2w" />
-      </concept>
+      <concept id="1070475354124" name="jetbrains.mps.baseLanguage.structure.ThisExpression" flags="nn" index="Xjq3P" />
       <concept id="1070475587102" name="jetbrains.mps.baseLanguage.structure.SuperConstructorInvocation" flags="nn" index="XkiVB" />
       <concept id="1070475926800" name="jetbrains.mps.baseLanguage.structure.StringLiteral" flags="nn" index="Xl_RD">
         <property id="1070475926801" name="value" index="Xl_RC" />
@@ -115,12 +113,9 @@
       </concept>
       <concept id="1068580123157" name="jetbrains.mps.baseLanguage.structure.Statement" flags="nn" index="3clFbH" />
       <concept id="1068580123159" name="jetbrains.mps.baseLanguage.structure.IfStatement" flags="nn" index="3clFbJ">
-        <property id="4467513934994662257" name="forceMultiLine" index="TyiWK" />
-        <property id="4467513934994662256" name="forceOneLine" index="TyiWL" />
         <child id="1082485599094" name="ifFalseStatement" index="9aQIa" />
         <child id="1068580123160" name="condition" index="3clFbw" />
         <child id="1068580123161" name="ifTrue" index="3clFbx" />
-        <child id="1206060520071" name="elsifClauses" index="3eNLev" />
       </concept>
       <concept id="1068580123136" name="jetbrains.mps.baseLanguage.structure.StatementList" flags="sn" stub="5293379017992965193" index="3clFbS">
         <child id="1068581517665" name="statement" index="3cqZAp" />
@@ -141,10 +136,6 @@
       </concept>
       <concept id="1068581242863" name="jetbrains.mps.baseLanguage.structure.LocalVariableDeclaration" flags="nr" index="3cpWsn" />
       <concept id="1068581517677" name="jetbrains.mps.baseLanguage.structure.VoidType" flags="in" index="3cqZAl" />
-      <concept id="1206060495898" name="jetbrains.mps.baseLanguage.structure.ElsifClause" flags="ng" index="3eNFk2">
-        <child id="1206060619838" name="condition" index="3eO9$A" />
-        <child id="1206060644605" name="statementList" index="3eOfB_" />
-      </concept>
       <concept id="1079359253375" name="jetbrains.mps.baseLanguage.structure.ParenthesizedExpression" flags="nn" index="1eOMI4">
         <child id="1079359253376" name="expression" index="1eOMHV" />
       </concept>
@@ -157,7 +148,6 @@
       </concept>
       <concept id="1212685548494" name="jetbrains.mps.baseLanguage.structure.ClassCreator" flags="nn" index="1pGfFk" />
       <concept id="1107461130800" name="jetbrains.mps.baseLanguage.structure.Classifier" flags="ng" index="3pOWGL">
-        <property id="521412098689998745" name="nonStatic" index="2bfB8j" />
         <child id="5375687026011219971" name="member" index="jymVt" unordered="true" />
       </concept>
       <concept id="1171903607971" name="jetbrains.mps.baseLanguage.structure.WildCardType" flags="in" index="3qTvmN" />
@@ -185,16 +175,8 @@
         <child id="1163668922816" name="ifTrue" index="3K4E3e" />
         <child id="1163668934364" name="ifFalse" index="3K4GZi" />
       </concept>
-      <concept id="6329021646629104957" name="jetbrains.mps.baseLanguage.structure.TextCommentPart" flags="nn" index="3SKdUq">
-        <property id="6329021646629104958" name="text" index="3SKdUp" />
-      </concept>
-      <concept id="6329021646629104954" name="jetbrains.mps.baseLanguage.structure.SingleLineComment" flags="nn" index="3SKdUt">
-        <child id="6329021646629175155" name="commentPart" index="3SKWNk" />
-      </concept>
       <concept id="1146644602865" name="jetbrains.mps.baseLanguage.structure.PublicVisibility" flags="nn" index="3Tm1VV" />
       <concept id="1146644623116" name="jetbrains.mps.baseLanguage.structure.PrivateVisibility" flags="nn" index="3Tm6S6" />
-      <concept id="1146644641414" name="jetbrains.mps.baseLanguage.structure.ProtectedVisibility" flags="nn" index="3Tmbuc" />
-      <concept id="1080120340718" name="jetbrains.mps.baseLanguage.structure.AndExpression" flags="nn" index="1Wc70l" />
     </language>
     <language id="f2801650-65d5-424e-bb1b-463a8781b786" name="jetbrains.mps.baseLanguage.javadoc">
       <concept id="5349172909345501395" name="jetbrains.mps.baseLanguage.javadoc.structure.BaseDocComment" flags="ng" index="P$AiS">
@@ -351,6 +333,42 @@
         <ref role="2AI5Lk" to="f8dg:~JCHR_Init" resolve="JCHR_Init" />
       </node>
     </node>
+    <node concept="2tJIrI" id="2h41Ezbxe8N" role="jymVt" />
+    <node concept="3clFb_" id="3mz2_dYqEdN" role="jymVt">
+      <property role="1EzhhJ" value="false" />
+      <property role="TrG5h" value="withMeta" />
+      <property role="od$2w" value="false" />
+      <property role="DiZV1" value="false" />
+      <property role="2aFKle" value="false" />
+      <node concept="37vLTG" id="3mz2_dYqKiz" role="3clF46">
+        <property role="TrG5h" value="metaLogical" />
+        <node concept="3uibUv" id="3mz2_dYqL9h" role="1tU5fm">
+          <ref role="3uigEE" to="45ys:7HUwyZauJhz" resolve="MetaLogical" />
+        </node>
+      </node>
+      <node concept="3clFbS" id="3mz2_dYqEdQ" role="3clF47">
+        <node concept="3clFbF" id="3mz2_dYqLkZ" role="3cqZAp">
+          <node concept="37vLTI" id="3mz2_dYqLl1" role="3clFbG">
+            <node concept="2OqwBi" id="3mz2_dYqLl5" role="37vLTJ">
+              <node concept="Xjq3P" id="3mz2_dYqLl8" role="2Oq$k0" />
+              <node concept="2OwXpG" id="3mz2_dYqLl4" role="2OqNvi">
+                <ref role="2Oxat5" node="3mz2_dYqLkV" resolve="metaLogical" />
+              </node>
+            </node>
+            <node concept="37vLTw" id="3mz2_dYqLl9" role="37vLTx">
+              <ref role="3cqZAo" node="3mz2_dYqKiz" resolve="metaLogical" />
+            </node>
+          </node>
+        </node>
+        <node concept="3clFbF" id="3mz2_dYqQgU" role="3cqZAp">
+          <node concept="Xjq3P" id="3mz2_dYqQgS" role="3clFbG" />
+        </node>
+      </node>
+      <node concept="3Tm1VV" id="3mz2_dYqDhF" role="1B3o_S" />
+      <node concept="3uibUv" id="3mz2_dYqNyR" role="3clF45">
+        <ref role="3uigEE" node="4U_yxogAknZ" resolve="AtomLogical" />
+      </node>
+    </node>
     <node concept="2tJIrI" id="4U_yxogCsEV" role="jymVt" />
     <node concept="3clFb_" id="dfChU1gcsX" role="jymVt">
       <property role="1EzhhJ" value="false" />
@@ -375,27 +393,7 @@
         <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
       </node>
     </node>
-    <node concept="2tJIrI" id="1Ns6gpY6S29" role="jymVt" />
-    <node concept="3clFb_" id="1Ns6gpY6DeD" role="jymVt">
-      <property role="TrG5h" value="asAtom" />
-      <node concept="3uibUv" id="1Ns6gpY6FOz" role="3clF45">
-        <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-      </node>
-      <node concept="3Tm1VV" id="1Ns6gpY6DeG" role="1B3o_S" />
-      <node concept="3clFbS" id="1Ns6gpY6DeH" role="3clF47">
-        <node concept="3cpWs6" id="1Ns6gpY6Kch" role="3cqZAp">
-          <node concept="2ShNRf" id="1Ns6gpY6Kci" role="3cqZAk">
-            <node concept="1pGfFk" id="1Ns6gpY6Kcj" role="2ShVmc">
-              <ref role="37wK5l" node="3HJTsBmSn3o" resolve="AtomLogical.AtomLogicalVar" />
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="2AHcQZ" id="dfChU1ktNm" role="2AJF6D">
-        <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-      </node>
-    </node>
-    <node concept="2tJIrI" id="7HUwyZaOjLx" role="jymVt" />
+    <node concept="2tJIrI" id="3mz2_dYyCli" role="jymVt" />
     <node concept="3clFb_" id="7HUwyZaOeBH" role="jymVt">
       <property role="1EzhhJ" value="false" />
       <property role="2aFKle" value="false" />
@@ -408,158 +406,33 @@
         </node>
       </node>
       <node concept="3clFbS" id="7HUwyZaOeBR" role="3clF47">
-        <node concept="3SKdUt" id="7HUwyZaOgx5" role="3cqZAp">
-          <node concept="3SKdUq" id="7HUwyZaOgx7" role="3SKWNk">
-            <property role="3SKdUp" value="FIXME: implement me" />
-          </node>
-        </node>
-        <node concept="YS8fn" id="7HUwyZaOg6C" role="3cqZAp">
-          <node concept="2ShNRf" id="7HUwyZaOg8$" role="YScLw">
-            <node concept="1pGfFk" id="7HUwyZaOgq0" role="2ShVmc">
-              <ref role="37wK5l" to="wyt6:~UnsupportedOperationException.&lt;init&gt;(java.lang.String)" resolve="UnsupportedOperationException" />
-              <node concept="Xl_RD" id="7HUwyZaOgs4" role="37wK5m">
-                <property role="Xl_RC" value="not implemented" />
+        <node concept="3clFbJ" id="3mz2_dYqMn1" role="3cqZAp">
+          <node concept="3clFbS" id="3mz2_dYqMn3" role="3clFbx">
+            <node concept="YS8fn" id="3mz2_dYqMJb" role="3cqZAp">
+              <node concept="2ShNRf" id="3mz2_dYqMMu" role="YScLw">
+                <node concept="1pGfFk" id="3mz2_dYqN04" role="2ShVmc">
+                  <ref role="37wK5l" to="wyt6:~NullPointerException.&lt;init&gt;()" resolve="NullPointerException" />
+                </node>
               </node>
             </node>
           </node>
+          <node concept="3clFbC" id="3mz2_dYqMy7" role="3clFbw">
+            <node concept="10Nm6u" id="3mz2_dYqMAm" role="3uHU7w" />
+            <node concept="37vLTw" id="3mz2_dYqMt_" role="3uHU7B">
+              <ref role="3cqZAo" node="3mz2_dYqLkV" resolve="metaLogical" />
+            </node>
+          </node>
+        </node>
+        <node concept="3clFbF" id="3mz2_dYqNgJ" role="3cqZAp">
+          <node concept="37vLTw" id="3mz2_dYqNgH" role="3clFbG">
+            <ref role="3cqZAo" node="3mz2_dYqLkV" resolve="metaLogical" />
+          </node>
         </node>
       </node>
       <node concept="2AHcQZ" id="7HUwyZaOhSh" role="2AJF6D">
         <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
       </node>
     </node>
-    <node concept="2tJIrI" id="7MlQDeOydKQ" role="jymVt" />
-    <node concept="3clFb_" id="7MlQDeOycM5" role="jymVt">
-      <property role="1EzhhJ" value="false" />
-      <property role="TrG5h" value="asAtom" />
-      <node concept="3uibUv" id="7MlQDeOycM6" role="3clF45">
-        <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-      </node>
-      <node concept="3Tm1VV" id="7MlQDeOycM7" role="1B3o_S" />
-      <node concept="37vLTG" id="7MlQDeOycM9" role="3clF46">
-        <property role="TrG5h" value="prototype" />
-        <node concept="3uibUv" id="7MlQDeOycMa" role="1tU5fm">
-          <ref role="3uigEE" to="wyt6:~Class" resolve="Class" />
-          <node concept="3qUE_q" id="7MlQDeOycMb" role="11_B2D">
-            <node concept="3uibUv" id="7MlQDeOycMc" role="3qUE_r">
-              <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="3clFbS" id="7MlQDeOycMo" role="3clF47">
-        <node concept="3clFbJ" id="7MlQDeOysnR" role="3cqZAp">
-          <property role="TyiWK" value="true" />
-          <property role="TyiWL" value="false" />
-          <node concept="3clFbS" id="7MlQDeOysnT" role="3clFbx">
-            <node concept="YS8fn" id="7MlQDeOyvB1" role="3cqZAp">
-              <node concept="2ShNRf" id="7MlQDeOyvDm" role="YScLw">
-                <node concept="1pGfFk" id="7MlQDeOyvUW" role="2ShVmc">
-                  <ref role="37wK5l" to="wyt6:~IllegalStateException.&lt;init&gt;(java.lang.String)" resolve="IllegalStateException" />
-                  <node concept="Xl_RD" id="7MlQDeOyvYY" role="37wK5m">
-                    <property role="Xl_RC" value="prototype already set" />
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-          <node concept="1Wc70l" id="3VqIndedLVx" role="3clFbw">
-            <node concept="3y3z36" id="3VqIndedOpj" role="3uHU7w">
-              <node concept="37vLTw" id="3VqIndedOvU" role="3uHU7w">
-                <ref role="3cqZAo" node="7MlQDeOycM9" resolve="prototype" />
-              </node>
-              <node concept="2OqwBi" id="3VqIndedMrl" role="3uHU7B">
-                <node concept="Xjq3P" id="3VqIndedMae" role="2Oq$k0" />
-                <node concept="2OwXpG" id="3VqIndedNyC" role="2OqNvi">
-                  <ref role="2Oxat5" node="7MlQDeOyfvd" resolve="prototype" />
-                </node>
-              </node>
-            </node>
-            <node concept="3y3z36" id="7MlQDeOytDY" role="3uHU7B">
-              <node concept="2OqwBi" id="7MlQDeOyuha" role="3uHU7B">
-                <node concept="Xjq3P" id="7MlQDeOytUj" role="2Oq$k0" />
-                <node concept="2OwXpG" id="7MlQDeOyvno" role="2OqNvi">
-                  <ref role="2Oxat5" node="7MlQDeOyfvd" resolve="prototype" />
-                </node>
-              </node>
-              <node concept="10Nm6u" id="7MlQDeOytRG" role="3uHU7w" />
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbH" id="3VqIndedOHI" role="3cqZAp" />
-        <node concept="3clFbF" id="7MlQDeOyfvj" role="3cqZAp">
-          <node concept="37vLTI" id="7MlQDeOyfvl" role="3clFbG">
-            <node concept="2OqwBi" id="7MlQDeOyfvp" role="37vLTJ">
-              <node concept="Xjq3P" id="7MlQDeOyfvs" role="2Oq$k0" />
-              <node concept="2OwXpG" id="7MlQDeOyfvo" role="2OqNvi">
-                <ref role="2Oxat5" node="7MlQDeOyfvd" resolve="prototype" />
-              </node>
-            </node>
-            <node concept="37vLTw" id="7MlQDeOyfvt" role="37vLTx">
-              <ref role="3cqZAo" node="7MlQDeOycM9" resolve="prototype" />
-            </node>
-          </node>
-        </node>
-        <node concept="3cpWs6" id="7MlQDeOyg$e" role="3cqZAp">
-          <node concept="1rXfSq" id="7MlQDeOyhw3" role="3cqZAk">
-            <ref role="37wK5l" node="1Ns6gpY6DeD" resolve="asAtom" />
-          </node>
-        </node>
-      </node>
-      <node concept="2AHcQZ" id="7MlQDeOyeEZ" role="2AJF6D">
-        <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-      </node>
-    </node>
-    <node concept="2tJIrI" id="2ev$9JFO6zk" role="jymVt" />
-    <node concept="3clFb_" id="6Sag3KsvpQ0" role="jymVt">
-      <property role="1EzhhJ" value="false" />
-      <property role="TrG5h" value="isValid" />
-      <node concept="37vLTG" id="6Sag3KsvpQ1" role="3clF46">
-        <property role="TrG5h" value="prototype" />
-        <node concept="3uibUv" id="6Sag3KsvpQ2" role="1tU5fm">
-          <ref role="3uigEE" to="wyt6:~Class" resolve="Class" />
-          <node concept="3qUE_q" id="6Sag3KsvpQ3" role="11_B2D">
-            <node concept="3uibUv" id="6Sag3KsvpQ4" role="3qUE_r">
-              <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="10P_77" id="6Sag3KsvpQ5" role="3clF45" />
-      <node concept="3Tm1VV" id="6Sag3KsvpQ6" role="1B3o_S" />
-      <node concept="3clFbS" id="6Sag3KsvpQj" role="3clF47">
-        <node concept="3clFbF" id="6Sag3KsvtdR" role="3cqZAp">
-          <node concept="3K4zz7" id="6Sag3KsvvQR" role="3clFbG">
-            <node concept="3clFbC" id="6Sag3Ksvz3O" role="3K4E3e">
-              <node concept="37vLTw" id="6Sag3Ksvzn_" role="3uHU7w">
-                <ref role="3cqZAo" node="6Sag3KsvpQ1" resolve="prototype" />
-              </node>
-              <node concept="2OqwBi" id="6Sag3Ksvwl5" role="3uHU7B">
-                <node concept="Xjq3P" id="6Sag3Ksvw7E" role="2Oq$k0" />
-                <node concept="2OwXpG" id="6Sag3KsvydU" role="2OqNvi">
-                  <ref role="2Oxat5" node="7MlQDeOyfvd" resolve="prototype" />
-                </node>
-              </node>
-            </node>
-            <node concept="3clFbT" id="6Sag3KsvzCy" role="3K4GZi">
-              <property role="3clFbU" value="true" />
-            </node>
-            <node concept="3y3z36" id="6Sag3KsvvJx" role="3K4Cdx">
-              <node concept="10Nm6u" id="6Sag3KsvvNn" role="3uHU7w" />
-              <node concept="2OqwBi" id="6Sag3KsvtFH" role="3uHU7B">
-                <node concept="Xjq3P" id="6Sag3KsvtdQ" role="2Oq$k0" />
-                <node concept="2OwXpG" id="6Sag3KsvuPK" role="2OqNvi">
-                  <ref role="2Oxat5" node="7MlQDeOyfvd" resolve="prototype" />
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="2AHcQZ" id="6Sag3Ksvr6w" role="2AJF6D">
-        <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-      </node>
-    </node>
     <node concept="2tJIrI" id="2ev$9JFO5ru" role="jymVt" />
     <node concept="3clFb_" id="5NuEpF1xPNu" role="jymVt">
       <property role="1EzhhJ" value="false" />
@@ -573,7 +446,7 @@
           <node concept="3cpWsn" id="5NuEpF1xSwz" role="3cpWs9">
             <property role="TrG5h" value="repr" />
             <node concept="3uibUv" id="7HUwyZazx80" role="1tU5fm">
-              <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
+              <ref role="3uigEE" to="45ys:1mP5b6jQP$C" resolve="Logical" />
               <node concept="3uibUv" id="7HUwyZazx81" role="11_B2D">
                 <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
               </node>
@@ -670,393 +543,6 @@
         <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
       </node>
     </node>
-    <node concept="2tJIrI" id="2h41Ezbxe8N" role="jymVt" />
-    <node concept="3clFb_" id="6HT7BWBMwRc" role="jymVt">
-      <property role="TrG5h" value="atomValue" />
-      <property role="1EzhhJ" value="false" />
-      <node concept="3uibUv" id="6HT7BWBNHCx" role="3clF45">
-        <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-      </node>
-      <node concept="3Tmbuc" id="6HT7BWBMwRg" role="1B3o_S" />
-      <node concept="3clFbS" id="6HT7BWBMwRp" role="3clF47">
-        <node concept="3cpWs8" id="6HT7BWBNRfv" role="3cqZAp">
-          <node concept="3cpWsn" id="6HT7BWBNRfw" role="3cpWs9">
-            <property role="TrG5h" value="val" />
-            <node concept="3uibUv" id="6HT7BWBNRfu" role="1tU5fm">
-              <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-            </node>
-            <node concept="2OqwBi" id="6HT7BWBNRfx" role="33vP2m">
-              <node concept="1rXfSq" id="6HT7BWBNRfy" role="2Oq$k0">
-                <ref role="37wK5l" node="dfChU1gcsX" resolve="findRoot" />
-              </node>
-              <node concept="liA8E" id="6HT7BWBNRfz" role="2OqNvi">
-                <ref role="37wK5l" to="95zw:3HJTsBmBZ0h" resolve="value" />
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbJ" id="6HT7BWBMzt1" role="3cqZAp">
-          <property role="TyiWK" value="true" />
-          <property role="TyiWL" value="false" />
-          <node concept="3clFbS" id="6HT7BWBMzt2" role="3clFbx">
-            <node concept="YS8fn" id="6HT7BWBMzt3" role="3cqZAp">
-              <node concept="2ShNRf" id="6HT7BWBMzt4" role="YScLw">
-                <node concept="1pGfFk" id="6HT7BWBMzt5" role="2ShVmc">
-                  <ref role="37wK5l" to="wyt6:~IllegalStateException.&lt;init&gt;(java.lang.String)" resolve="IllegalStateException" />
-                  <node concept="Xl_RD" id="6HT7BWBMzt6" role="37wK5m">
-                    <property role="Xl_RC" value="prorotype constraint violation" />
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-          <node concept="1Wc70l" id="6HT7BWBMzt7" role="3clFbw">
-            <node concept="3fqX7Q" id="6HT7BWBMzt8" role="3uHU7w">
-              <node concept="2OqwBi" id="6HT7BWBMzt9" role="3fr31v">
-                <node concept="37vLTw" id="6HT7BWBMzta" role="2Oq$k0">
-                  <ref role="3cqZAo" node="7MlQDeOyfvd" resolve="prototype" />
-                </node>
-                <node concept="liA8E" id="6HT7BWBMztb" role="2OqNvi">
-                  <ref role="37wK5l" to="wyt6:~Class.isAssignableFrom(java.lang.Class):boolean" resolve="isAssignableFrom" />
-                  <node concept="2OqwBi" id="6HT7BWBMztc" role="37wK5m">
-                    <node concept="37vLTw" id="6HT7BWBNSwT" role="2Oq$k0">
-                      <ref role="3cqZAo" node="6HT7BWBNRfw" resolve="val" />
-                    </node>
-                    <node concept="liA8E" id="6HT7BWBMzte" role="2OqNvi">
-                      <ref role="37wK5l" to="wyt6:~Object.getClass():java.lang.Class" resolve="getClass" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3y3z36" id="6HT7BWBMztf" role="3uHU7B">
-              <node concept="37vLTw" id="6HT7BWBMztg" role="3uHU7B">
-                <ref role="3cqZAo" node="7MlQDeOyfvd" resolve="prototype" />
-              </node>
-              <node concept="10Nm6u" id="6HT7BWBMzth" role="3uHU7w" />
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbF" id="6HT7BWBNT7e" role="3cqZAp">
-          <node concept="37vLTw" id="6HT7BWBNT7c" role="3clFbG">
-            <ref role="3cqZAo" node="6HT7BWBNRfw" resolve="val" />
-          </node>
-        </node>
-      </node>
-    </node>
-    <node concept="2tJIrI" id="6HT7BWBMyhy" role="jymVt" />
-    <node concept="312cEu" id="3HJTsBmSn3l" role="jymVt">
-      <property role="TrG5h" value="AtomLogicalVar" />
-      <property role="2bfB8j" value="true" />
-      <node concept="2tJIrI" id="3HJTsBmSn3m" role="jymVt" />
-      <node concept="3Tm1VV" id="3HJTsBmSn3n" role="1B3o_S" />
-      <node concept="3clFbW" id="3HJTsBmSn3o" role="jymVt">
-        <node concept="3cqZAl" id="3HJTsBmSn3p" role="3clF45" />
-        <node concept="3Tm1VV" id="3HJTsBmSn3q" role="1B3o_S" />
-        <node concept="3clFbS" id="3HJTsBmSn3r" role="3clF47">
-          <node concept="XkiVB" id="2h41EzbxxP9" role="3cqZAp">
-            <ref role="37wK5l" to="ie8e:uNmovXiEVu" resolve="Variable" />
-            <node concept="1rXfSq" id="2h41Ezbx$v8" role="37wK5m">
-              <ref role="37wK5l" to="95zw:3HJTsBmCy5P" resolve="name" />
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="2tJIrI" id="2h41Ezbx2H3" role="jymVt" />
-      <node concept="3clFb_" id="2h41EzbwS8H" role="jymVt">
-        <property role="1EzhhJ" value="false" />
-        <property role="TrG5h" value="get" />
-        <property role="DiZV1" value="false" />
-        <property role="od$2w" value="false" />
-        <node concept="3Tm1VV" id="2h41EzbwS8I" role="1B3o_S" />
-        <node concept="3uibUv" id="573vQv1pew4" role="3clF45">
-          <ref role="3uigEE" to="yt73:~Term" resolve="Term" />
-        </node>
-        <node concept="3clFbS" id="2h41EzbwS8M" role="3clF47">
-          <node concept="3clFbJ" id="2h41EzbxGVG" role="3cqZAp">
-            <node concept="3clFbS" id="2h41EzbxGVI" role="3clFbx">
-              <node concept="3cpWs6" id="2h41EzbxJTK" role="3cqZAp">
-                <node concept="1rXfSq" id="2h41EzbxKA7" role="3cqZAk">
-                  <ref role="37wK5l" node="6HT7BWBMwRc" resolve="atomValue" />
-                </node>
-              </node>
-              <node concept="3clFbH" id="6HT7BWBPJuI" role="3cqZAp" />
-            </node>
-            <node concept="1rXfSq" id="2h41EzbxGYR" role="3clFbw">
-              <ref role="37wK5l" to="95zw:3HJTsBmC6RD" resolve="isBound" />
-            </node>
-            <node concept="9aQIb" id="2h41EzbxH5p" role="9aQIa">
-              <node concept="3clFbS" id="2h41EzbxH5q" role="9aQI4">
-                <node concept="3cpWs6" id="2h41EzbxH7Z" role="3cqZAp">
-                  <node concept="Xjq3P" id="2h41EzbxH9z" role="3cqZAk" />
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="2AHcQZ" id="2h41Ezbx5ZA" role="2AJF6D">
-          <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-        </node>
-      </node>
-      <node concept="2tJIrI" id="2h41Ezbx5gj" role="jymVt" />
-      <node concept="3clFb_" id="2h41EzbwS8P" role="jymVt">
-        <property role="1EzhhJ" value="false" />
-        <property role="TrG5h" value="is" />
-        <property role="DiZV1" value="false" />
-        <property role="od$2w" value="false" />
-        <node concept="3Tm1VV" id="2h41EzbwS8Q" role="1B3o_S" />
-        <node concept="37vLTG" id="2h41EzbwS8R" role="3clF46">
-          <property role="TrG5h" value="kind" />
-          <property role="3TUv4t" value="false" />
-          <node concept="3uibUv" id="573vQv1pfmQ" role="1tU5fm">
-            <ref role="3uigEE" to="yt73:~Term$Kind" resolve="Term.Kind" />
-          </node>
-        </node>
-        <node concept="10P_77" id="2h41EzbwS8U" role="3clF45" />
-        <node concept="3clFbS" id="2h41EzbwS8W" role="3clF47">
-          <node concept="3clFbJ" id="2h41EzbxNr9" role="3cqZAp">
-            <node concept="3clFbS" id="2h41EzbxNra" role="3clFbx">
-              <node concept="3cpWs6" id="2h41EzbxNA6" role="3cqZAp">
-                <node concept="3clFbC" id="2h41EzbxUn2" role="3cqZAk">
-                  <node concept="37vLTw" id="2h41EzbxV2Z" role="3uHU7w">
-                    <ref role="3cqZAo" node="2h41EzbwS8R" resolve="kind" />
-                  </node>
-                  <node concept="Rm8GO" id="2h41EzbxTzV" role="3uHU7B">
-                    <ref role="1Px2BO" to="yt73:~Term$Kind" resolve="Term.Kind" />
-                    <ref role="Rm8GQ" to="yt73:~Term$Kind.REF" resolve="REF" />
-                  </node>
-                </node>
-              </node>
-              <node concept="3clFbH" id="6HT7BWBQgbR" role="3cqZAp" />
-            </node>
-            <node concept="1rXfSq" id="2h41EzbxNuf" role="3clFbw">
-              <ref role="37wK5l" to="95zw:3HJTsBmC6RD" resolve="isBound" />
-            </node>
-            <node concept="9aQIb" id="2h41EzbxVHT" role="9aQIa">
-              <node concept="3clFbS" id="2h41EzbxVHU" role="9aQI4">
-                <node concept="3cpWs6" id="2h41EzbxWqe" role="3cqZAp">
-                  <node concept="3clFbC" id="2h41EzbxYi0" role="3cqZAk">
-                    <node concept="37vLTw" id="2h41EzbxYIt" role="3uHU7w">
-                      <ref role="3cqZAo" node="2h41EzbwS8R" resolve="kind" />
-                    </node>
-                    <node concept="Rm8GO" id="2h41EzbxXxv" role="3uHU7B">
-                      <ref role="1Px2BO" to="yt73:~Term$Kind" resolve="Term.Kind" />
-                      <ref role="Rm8GQ" to="yt73:~Term$Kind.VAR" resolve="VAR" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="2AHcQZ" id="2h41Ezbx7tm" role="2AJF6D">
-          <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-        </node>
-      </node>
-      <node concept="2tJIrI" id="2h41Ezbx8bH" role="jymVt" />
-      <node concept="3clFb_" id="3HJTsBmSn3F" role="jymVt">
-        <property role="TrG5h" value="logical" />
-        <node concept="3uibUv" id="3HJTsBmSn3G" role="3clF45">
-          <ref role="3uigEE" node="4U_yxogAknZ" resolve="AtomLogical" />
-        </node>
-        <node concept="3Tm1VV" id="3HJTsBmSn3H" role="1B3o_S" />
-        <node concept="3clFbS" id="3HJTsBmSn3I" role="3clF47">
-          <node concept="3clFbF" id="3HJTsBmSn3J" role="3cqZAp">
-            <node concept="Xjq3P" id="3HJTsBmToxQ" role="3clFbG">
-              <ref role="1HBi2w" node="4U_yxogAknZ" resolve="AtomLogical" />
-            </node>
-          </node>
-        </node>
-        <node concept="2AHcQZ" id="3HJTsBmSn3L" role="2AJF6D">
-          <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-        </node>
-      </node>
-      <node concept="2tJIrI" id="2DKqMqOj7IE" role="jymVt" />
-      <node concept="3clFb_" id="2DKqMqOj8gF" role="jymVt">
-        <property role="TrG5h" value="isWildcard" />
-        <property role="1EzhhJ" value="false" />
-        <node concept="10P_77" id="2DKqMqOj8gG" role="3clF45" />
-        <node concept="3Tm1VV" id="2DKqMqOj8gH" role="1B3o_S" />
-        <node concept="3clFbS" id="2DKqMqOj8gL" role="3clF47">
-          <node concept="3clFbF" id="2DKqMqOjdRo" role="3cqZAp">
-            <node concept="2OqwBi" id="2DKqMqOjdRp" role="3clFbG">
-              <node concept="Xjq3P" id="2DKqMqOjdRq" role="2Oq$k0">
-                <ref role="1HBi2w" node="4U_yxogAknZ" resolve="AtomLogical" />
-              </node>
-              <node concept="liA8E" id="2DKqMqOjdRr" role="2OqNvi">
-                <ref role="37wK5l" to="95zw:2DKqMqOiEEz" resolve="isWildcard" />
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="2AHcQZ" id="2DKqMqOj8gM" role="2AJF6D">
-          <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-        </node>
-      </node>
-      <node concept="2tJIrI" id="2DKqMqOjahb" role="jymVt" />
-      <node concept="3clFb_" id="6Sag3Ksvc97" role="jymVt">
-        <property role="TrG5h" value="canRepresent" />
-        <property role="1EzhhJ" value="false" />
-        <node concept="37vLTG" id="6Sag3Ksvc98" role="3clF46">
-          <property role="TrG5h" value="klass" />
-          <node concept="3uibUv" id="6Sag3Ksvc99" role="1tU5fm">
-            <ref role="3uigEE" to="wyt6:~Class" resolve="Class" />
-            <node concept="3qUE_q" id="6Sag3Ksvc9a" role="11_B2D">
-              <node concept="3uibUv" id="6Sag3Ksvc9b" role="3qUE_r">
-                <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="10P_77" id="6Sag3Ksvc9c" role="3clF45" />
-        <node concept="3Tm1VV" id="6Sag3Ksvc9d" role="1B3o_S" />
-        <node concept="3clFbS" id="6Sag3Ksvc9h" role="3clF47">
-          <node concept="3clFbF" id="6Sag3KsvzPQ" role="3cqZAp">
-            <node concept="1rXfSq" id="6Sag3KsvzPP" role="3clFbG">
-              <ref role="37wK5l" node="6Sag3KsvpQ0" resolve="isValid" />
-              <node concept="37vLTw" id="6Sag3Ksv$97" role="37wK5m">
-                <ref role="3cqZAo" node="6Sag3Ksvc98" resolve="klass" />
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="2AHcQZ" id="6Sag3Ksvc9i" role="2AJF6D">
-          <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-        </node>
-      </node>
-      <node concept="2tJIrI" id="6Sag3Ksvdhv" role="jymVt" />
-      <node concept="3clFb_" id="3HJTsBmSn4t" role="jymVt">
-        <property role="1EzhhJ" value="false" />
-        <property role="TrG5h" value="toString" />
-        <property role="DiZV1" value="false" />
-        <property role="IEkAT" value="false" />
-        <node concept="3Tm1VV" id="3HJTsBmSn4u" role="1B3o_S" />
-        <node concept="17QB3L" id="3HJTsBmSn4v" role="3clF45" />
-        <node concept="3clFbS" id="3HJTsBmSn4w" role="3clF47">
-          <node concept="3clFbF" id="3HJTsBmSn4x" role="3cqZAp">
-            <node concept="2OqwBi" id="3HJTsBmSn4y" role="3clFbG">
-              <node concept="1rXfSq" id="3HJTsBmTsLO" role="2Oq$k0">
-                <ref role="37wK5l" node="3HJTsBmSn3F" resolve="logical" />
-              </node>
-              <node concept="liA8E" id="3HJTsBmSn4$" role="2OqNvi">
-                <ref role="37wK5l" to="95zw:3HJTsBmCy5P" resolve="name" />
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="2AHcQZ" id="3HJTsBmSn4_" role="2AJF6D">
-          <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-        </node>
-      </node>
-      <node concept="2tJIrI" id="3HJTsBmSn3M" role="jymVt" />
-      <node concept="3clFb_" id="3HJTsBmSn3N" role="jymVt">
-        <property role="1EzhhJ" value="false" />
-        <property role="TrG5h" value="hashCode" />
-        <property role="DiZV1" value="false" />
-        <property role="IEkAT" value="false" />
-        <node concept="3Tm1VV" id="3HJTsBmSn3O" role="1B3o_S" />
-        <node concept="10Oyi0" id="3HJTsBmSn3P" role="3clF45" />
-        <node concept="3clFbS" id="3HJTsBmSn3Q" role="3clF47">
-          <node concept="3clFbF" id="3HJTsBmSn3R" role="3cqZAp">
-            <node concept="3cpWs3" id="3HJTsBmSn3S" role="3clFbG">
-              <node concept="3cmrfG" id="3HJTsBmSn3T" role="3uHU7w">
-                <property role="3cmrfH" value="31" />
-              </node>
-              <node concept="17qRlL" id="3HJTsBmSn3U" role="3uHU7B">
-                <node concept="3cmrfG" id="3HJTsBmSn3Y" role="3uHU7w">
-                  <property role="3cmrfH" value="17" />
-                </node>
-                <node concept="2OqwBi" id="3HJTsBmTmPB" role="3uHU7B">
-                  <node concept="Xjq3P" id="3HJTsBmTmBJ" role="2Oq$k0">
-                    <ref role="1HBi2w" node="4U_yxogAknZ" resolve="AtomLogical" />
-                  </node>
-                  <node concept="liA8E" id="3HJTsBmTo2d" role="2OqNvi">
-                    <ref role="37wK5l" to="95zw:3HJTsBmCeUf" resolve="hashCode" />
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="2AHcQZ" id="3HJTsBmSn3Z" role="2AJF6D">
-          <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-        </node>
-      </node>
-      <node concept="2tJIrI" id="3HJTsBmSn40" role="jymVt" />
-      <node concept="3clFb_" id="3HJTsBmSn41" role="jymVt">
-        <property role="1EzhhJ" value="false" />
-        <property role="TrG5h" value="equals" />
-        <property role="DiZV1" value="false" />
-        <property role="IEkAT" value="false" />
-        <node concept="3Tm1VV" id="3HJTsBmSn42" role="1B3o_S" />
-        <node concept="10P_77" id="3HJTsBmSn43" role="3clF45" />
-        <node concept="37vLTG" id="3HJTsBmSn44" role="3clF46">
-          <property role="TrG5h" value="that" />
-          <node concept="3uibUv" id="3HJTsBmSn45" role="1tU5fm">
-            <ref role="3uigEE" to="wyt6:~Object" resolve="Object" />
-          </node>
-        </node>
-        <node concept="3clFbS" id="3HJTsBmSn46" role="3clF47">
-          <node concept="3clFbJ" id="3HJTsBmSn47" role="3cqZAp">
-            <node concept="3clFbS" id="3HJTsBmSn48" role="3clFbx">
-              <node concept="3cpWs6" id="3HJTsBmSn49" role="3cqZAp">
-                <node concept="3clFbT" id="3HJTsBmSn4a" role="3cqZAk">
-                  <property role="3clFbU" value="false" />
-                </node>
-              </node>
-            </node>
-            <node concept="3fqX7Q" id="3HJTsBmSn4b" role="3clFbw">
-              <node concept="2ZW3vV" id="3HJTsBmSn4c" role="3fr31v">
-                <node concept="3uibUv" id="3HJTsBmSn4d" role="2ZW6by">
-                  <ref role="3uigEE" node="3HJTsBmSn3l" resolve="AtomLogical.AtomLogicalVar" />
-                </node>
-                <node concept="37vLTw" id="3HJTsBmSn4e" role="2ZW6bz">
-                  <ref role="3cqZAo" node="3HJTsBmSn44" resolve="that" />
-                </node>
-              </node>
-            </node>
-          </node>
-          <node concept="3cpWs6" id="3HJTsBmSn4f" role="3cqZAp">
-            <node concept="2OqwBi" id="3HJTsBmSn4g" role="3cqZAk">
-              <node concept="2OqwBi" id="3HJTsBmSn4h" role="2Oq$k0">
-                <node concept="Xjq3P" id="3HJTsBmSn4i" role="2Oq$k0" />
-                <node concept="liA8E" id="3HJTsBmTqlz" role="2OqNvi">
-                  <ref role="37wK5l" node="3HJTsBmSn3F" resolve="logical" />
-                </node>
-              </node>
-              <node concept="liA8E" id="3HJTsBmSn4k" role="2OqNvi">
-                <ref role="37wK5l" to="95zw:3HJTsBmCeTt" resolve="equals" />
-                <node concept="2OqwBi" id="3HJTsBmSn4l" role="37wK5m">
-                  <node concept="1eOMI4" id="3HJTsBmSn4m" role="2Oq$k0">
-                    <node concept="10QFUN" id="3HJTsBmSn4n" role="1eOMHV">
-                      <node concept="3uibUv" id="3HJTsBmSn4o" role="10QFUM">
-                        <ref role="3uigEE" node="3HJTsBmSn3l" resolve="AtomLogical.AtomLogicalVar" />
-                      </node>
-                      <node concept="37vLTw" id="3HJTsBmSn4p" role="10QFUP">
-                        <ref role="3cqZAo" node="3HJTsBmSn44" resolve="that" />
-                      </node>
-                    </node>
-                  </node>
-                  <node concept="liA8E" id="3HJTsBmTrTy" role="2OqNvi">
-                    <ref role="37wK5l" node="3HJTsBmSn3F" resolve="logical" />
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="2AHcQZ" id="3HJTsBmSn4r" role="2AJF6D">
-          <ref role="2AI5Lk" to="wyt6:~Override" resolve="Override" />
-        </node>
-      </node>
-      <node concept="2tJIrI" id="3HJTsBmSn4E" role="jymVt" />
-      <node concept="3uibUv" id="3HJTsBmSn4G" role="EKbjA">
-        <ref role="3uigEE" to="yg8f:46l0wJhtOD_" resolve="ILogicalVar" />
-      </node>
-      <node concept="3uibUv" id="2h41Ezbxu$Q" role="1zkMxy">
-        <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
-      </node>
-    </node>
     <node concept="3Tm1VV" id="4U_yxogAko0" role="1B3o_S" />
     <node concept="3uibUv" id="4U_yxogB8or" role="1zkMxy">
       <ref role="3uigEE" to="95zw:3HJTsBmBSJa" resolve="JchrLogical" />
@@ -1065,7 +551,7 @@
       </node>
     </node>
     <node concept="3uibUv" id="7HUwyZazx8k" role="EKbjA">
-      <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
+      <ref role="3uigEE" to="45ys:1mP5b6jQP$C" resolve="Logical" />
       <node concept="3uibUv" id="7HUwyZazx8l" role="11_B2D">
         <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
       </node>
@@ -1112,17 +598,12 @@
         </node>
       </node>
     </node>
-    <node concept="2tJIrI" id="7MlQDeOyjsA" role="jymVt" />
-    <node concept="312cEg" id="7MlQDeOyfvd" role="jymVt">
-      <property role="TrG5h" value="prototype" />
-      <node concept="3Tm6S6" id="7MlQDeOyfve" role="1B3o_S" />
-      <node concept="3uibUv" id="7MlQDeOyfvg" role="1tU5fm">
-        <ref role="3uigEE" to="wyt6:~Class" resolve="Class" />
-        <node concept="3qUE_q" id="7MlQDeOyfvh" role="11_B2D">
-          <node concept="3uibUv" id="7MlQDeOyfvi" role="3qUE_r">
-            <ref role="3uigEE" to="ie8e:1bm7a6EXvsP" resolve="Atom" />
-          </node>
-        </node>
+    <node concept="2tJIrI" id="3mz2_dYyUvA" role="jymVt" />
+    <node concept="312cEg" id="3mz2_dYqLkV" role="jymVt">
+      <property role="TrG5h" value="metaLogical" />
+      <node concept="3Tm6S6" id="3mz2_dYqLkW" role="1B3o_S" />
+      <node concept="3uibUv" id="3mz2_dYqLkY" role="1tU5fm">
+        <ref role="3uigEE" to="45ys:7HUwyZauJhz" resolve="MetaLogical" />
       </node>
     </node>
   </node>
@@ -1484,75 +965,42 @@
       <node concept="3Tm1VV" id="4TCblo5MWaI" role="1B3o_S" />
       <node concept="3clFbS" id="4TCblo5MWaM" role="3clF47">
         <node concept="3clFbJ" id="4TCblo5PbR3" role="3cqZAp">
-          <node concept="3clFbS" id="4TCblo5PbR5" role="3clFbx">
-            <node concept="3cpWs6" id="4TCblo5Pcx7" role="3cqZAp">
-              <node concept="2OqwBi" id="4TCblo5Pdoh" role="3cqZAk">
-                <node concept="1eOMI4" id="4TCblo5PcXr" role="2Oq$k0">
-                  <node concept="10QFUN" id="4TCblo5PcXo" role="1eOMHV">
-                    <node concept="3uibUv" id="4TCblo5PcXt" role="10QFUM">
-                      <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
-                    </node>
-                    <node concept="37vLTw" id="4TCblo5PcXu" role="10QFUP">
+          <node concept="3y3z36" id="4TCblo5PgbW" role="3clFbw">
+            <node concept="10Nm6u" id="4TCblo5Pgg9" role="3uHU7w" />
+            <node concept="2OqwBi" id="4TCblo5PfKR" role="3uHU7B">
+              <node concept="37vLTw" id="4TCblo5Pf_R" role="2Oq$k0">
+                <ref role="3cqZAo" node="4TCblo5MOOn" resolve="logical" />
+              </node>
+              <node concept="liA8E" id="4TCblo5PfRq" role="2OqNvi">
+                <ref role="37wK5l" to="45ys:7HUwyZaOd5Y" resolve="metaLogical" />
+              </node>
+            </node>
+          </node>
+          <node concept="3clFbS" id="4TCblo5Pf7P" role="3clFbx">
+            <node concept="3cpWs6" id="4TCblo5PgQh" role="3cqZAp">
+              <node concept="2OqwBi" id="6OUp3PsSGSl" role="3cqZAk">
+                <node concept="2OqwBi" id="4TCblo5PiAX" role="2Oq$k0">
+                  <node concept="2OqwBi" id="4TCblo5PhFQ" role="2Oq$k0">
+                    <node concept="37vLTw" id="4TCblo5Phlx" role="2Oq$k0">
                       <ref role="3cqZAo" node="4TCblo5MOOn" resolve="logical" />
                     </node>
+                    <node concept="liA8E" id="4TCblo5Pi8Z" role="2OqNvi">
+                      <ref role="37wK5l" to="45ys:7HUwyZaOd5Y" resolve="metaLogical" />
+                    </node>
+                  </node>
+                  <node concept="liA8E" id="4TCblo5Pj6t" role="2OqNvi">
+                    <ref role="37wK5l" to="45ys:7HUwyZaC3Q7" resolve="type" />
                   </node>
                 </node>
-                <node concept="liA8E" id="4TCblo5PdR8" role="2OqNvi">
-                  <ref role="37wK5l" to="yg8f:6Sag3Ksvh9N" resolve="isValid" />
-                  <node concept="37vLTw" id="4TCblo5PeiC" role="37wK5m">
+                <node concept="liA8E" id="6OUp3PsSHqC" role="2OqNvi">
+                  <ref role="37wK5l" to="wyt6:~Object.equals(java.lang.Object):boolean" resolve="equals" />
+                  <node concept="37vLTw" id="6OUp3PsSJNn" role="37wK5m">
                     <ref role="3cqZAo" node="4TCblo5MWaD" resolve="klass" />
                   </node>
                 </node>
               </node>
             </node>
-            <node concept="3clFbH" id="4TCblo5Pgo0" role="3cqZAp" />
-          </node>
-          <node concept="2ZW3vV" id="4TCblo5PciH" role="3clFbw">
-            <node concept="3uibUv" id="4TCblo5PcsY" role="2ZW6by">
-              <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
-            </node>
-            <node concept="37vLTw" id="4TCblo5PbWN" role="2ZW6bz">
-              <ref role="3cqZAo" node="4TCblo5MOOn" resolve="logical" />
-            </node>
-          </node>
-          <node concept="3eNFk2" id="4TCblo5Pf7O" role="3eNLev">
-            <node concept="3clFbS" id="4TCblo5Pf7P" role="3eOfB_">
-              <node concept="3cpWs6" id="4TCblo5PgQh" role="3cqZAp">
-                <node concept="2OqwBi" id="6OUp3PsSGSl" role="3cqZAk">
-                  <node concept="2OqwBi" id="4TCblo5PiAX" role="2Oq$k0">
-                    <node concept="2OqwBi" id="4TCblo5PhFQ" role="2Oq$k0">
-                      <node concept="37vLTw" id="4TCblo5Phlx" role="2Oq$k0">
-                        <ref role="3cqZAo" node="4TCblo5MOOn" resolve="logical" />
-                      </node>
-                      <node concept="liA8E" id="4TCblo5Pi8Z" role="2OqNvi">
-                        <ref role="37wK5l" to="45ys:7HUwyZaOd5Y" resolve="metaLogical" />
-                      </node>
-                    </node>
-                    <node concept="liA8E" id="4TCblo5Pj6t" role="2OqNvi">
-                      <ref role="37wK5l" to="45ys:7HUwyZaC3Q7" resolve="type" />
-                    </node>
-                  </node>
-                  <node concept="liA8E" id="6OUp3PsSHqC" role="2OqNvi">
-                    <ref role="37wK5l" to="wyt6:~Object.equals(java.lang.Object):boolean" resolve="equals" />
-                    <node concept="37vLTw" id="6OUp3PsSJNn" role="37wK5m">
-                      <ref role="3cqZAo" node="4TCblo5MWaD" resolve="klass" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-              <node concept="3clFbH" id="4TCblo5PlEX" role="3cqZAp" />
-            </node>
-            <node concept="3y3z36" id="4TCblo5PgbW" role="3eO9$A">
-              <node concept="10Nm6u" id="4TCblo5Pgg9" role="3uHU7w" />
-              <node concept="2OqwBi" id="4TCblo5PfKR" role="3uHU7B">
-                <node concept="37vLTw" id="4TCblo5Pf_R" role="2Oq$k0">
-                  <ref role="3cqZAo" node="4TCblo5MOOn" resolve="logical" />
-                </node>
-                <node concept="liA8E" id="4TCblo5PfRq" role="2OqNvi">
-                  <ref role="37wK5l" to="45ys:7HUwyZaOd5Y" resolve="metaLogical" />
-                </node>
-              </node>
-            </node>
+            <node concept="3clFbH" id="4TCblo5PlEX" role="3cqZAp" />
           </node>
         </node>
         <node concept="3clFbF" id="4TCblo5PmcG" role="3cqZAp">
diff --git a/logic/solutions/jetbrains.mps.logic.jchr/models/jetbrains/mps/logic/jchr/predicate.mps b/logic/solutions/jetbrains.mps.logic.jchr/models/jetbrains/mps/logic/jchr/predicate.mps
index 467145b2..f08df4c3 100644
--- a/logic/solutions/jetbrains.mps.logic.jchr/models/jetbrains/mps/logic/jchr/predicate.mps
+++ b/logic/solutions/jetbrains.mps.logic.jchr/models/jetbrains/mps/logic/jchr/predicate.mps
@@ -1932,7 +1932,7 @@
       <property role="TrG5h" value="T" />
     </node>
     <node concept="3uibUv" id="3HJTsBmBTqG" role="EKbjA">
-      <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
+      <ref role="3uigEE" to="45ys:1mP5b6jQP$C" resolve="Logical" />
       <node concept="16syzq" id="3HJTsBmBTr8" role="11_B2D">
         <ref role="16sUi3" node="3HJTsBmBSUN" resolve="T" />
       </node>
diff --git a/logic/solutions/jetbrains.mps.logic.test/models/jetbrains/mps/logic/test/logical.mps b/logic/solutions/jetbrains.mps.logic.test/models/jetbrains/mps/logic/test/logical.mps
index 28b8a7fb..a616ef94 100644
--- a/logic/solutions/jetbrains.mps.logic.test/models/jetbrains/mps/logic/test/logical.mps
+++ b/logic/solutions/jetbrains.mps.logic.test/models/jetbrains/mps/logic/test/logical.mps
@@ -882,20 +882,33 @@
               <node concept="3uibUv" id="7FFmDVAOQYX" role="1tU5fm">
                 <ref role="3uigEE" to="oy3s:4U_yxogAknZ" resolve="AtomLogical" />
               </node>
-              <node concept="2ShNRf" id="1OShD0HAz3P" role="33vP2m">
-                <node concept="1pGfFk" id="1OShD0HAz3Q" role="2ShVmc">
-                  <ref role="37wK5l" to="oy3s:6SkxsM$2Uu7" resolve="AtomLogical" />
-                  <node concept="1oi1Uc" id="1OShD0HAz3R" role="37wK5m">
-                    <node concept="1oi5UN" id="1OShD0HA$aZ" role="1oi0x0">
-                      <node concept="1oi5Wm" id="1OShD0HA$b0" role="1ojpOf">
-                        <property role="TrG5h" value="qux" />
-                        <node concept="1oi5XN" id="1OShD0HA$b1" role="1oi5zu">
-                          <property role="1oi5yK" value="xyz" />
+              <node concept="2OqwBi" id="3mz2_dYr2wC" role="33vP2m">
+                <node concept="2ShNRf" id="1OShD0HAz3P" role="2Oq$k0">
+                  <node concept="1pGfFk" id="1OShD0HAz3Q" role="2ShVmc">
+                    <ref role="37wK5l" to="oy3s:6SkxsM$2Uu7" resolve="AtomLogical" />
+                    <node concept="1oi1Uc" id="1OShD0HAz3R" role="37wK5m">
+                      <node concept="1oi5UN" id="1OShD0HA$aZ" role="1oi0x0">
+                        <node concept="1oi5Wm" id="1OShD0HA$b0" role="1ojpOf">
+                          <property role="TrG5h" value="qux" />
+                          <node concept="1oi5XN" id="1OShD0HA$b1" role="1oi5zu">
+                            <property role="1oi5yK" value="xyz" />
+                          </node>
                         </node>
                       </node>
                     </node>
                   </node>
                 </node>
+                <node concept="liA8E" id="3mz2_dYr3jb" role="2OqNvi">
+                  <ref role="37wK5l" to="oy3s:3mz2_dYqEdN" resolve="withMeta" />
+                  <node concept="2ShNRf" id="3mz2_dYr3rP" role="37wK5m">
+                    <node concept="1pGfFk" id="3mz2_dYr3EY" role="2ShVmc">
+                      <ref role="37wK5l" to="45ys:7nPD14NON$Y" resolve="MetaLogical" />
+                      <node concept="3VsKOn" id="3mz2_dYr3os" role="37wK5m">
+                        <ref role="3VsUkX" to="ie8e:5JQSuNswOXL" resolve="StemFunc" />
+                      </node>
+                    </node>
+                  </node>
+                </node>
               </node>
             </node>
           </node>
@@ -993,26 +1006,39 @@
               <node concept="3uibUv" id="7FFmDVAOQZB" role="1tU5fm">
                 <ref role="3uigEE" to="oy3s:4U_yxogAknZ" resolve="AtomLogical" />
               </node>
-              <node concept="2ShNRf" id="1OShD0HRNoH" role="33vP2m">
-                <node concept="1pGfFk" id="1OShD0HRNoI" role="2ShVmc">
-                  <ref role="37wK5l" to="oy3s:6SkxsM$2Uu7" resolve="AtomLogical" />
-                  <node concept="1oi1Uc" id="1OShD0HRNoJ" role="37wK5m">
-                    <node concept="KCUsM" id="1OShD0HTdS0" role="1oi0x0">
-                      <node concept="1oi5UN" id="1OShD0HTdS1" role="KCVpo">
-                        <node concept="1oi5Wm" id="1OShD0HTdS2" role="1ojpOf">
-                          <property role="TrG5h" value="bar" />
-                          <node concept="1oi5XN" id="1OShD0HTdS3" role="1oi5zu">
-                            <property role="1oi5yK" value="abc" />
+              <node concept="2OqwBi" id="3mz2_dYqWV9" role="33vP2m">
+                <node concept="2ShNRf" id="1OShD0HRNoH" role="2Oq$k0">
+                  <node concept="1pGfFk" id="1OShD0HRNoI" role="2ShVmc">
+                    <ref role="37wK5l" to="oy3s:6SkxsM$2Uu7" resolve="AtomLogical" />
+                    <node concept="1oi1Uc" id="1OShD0HRNoJ" role="37wK5m">
+                      <node concept="KCUsM" id="1OShD0HTdS0" role="1oi0x0">
+                        <node concept="1oi5UN" id="1OShD0HTdS1" role="KCVpo">
+                          <node concept="1oi5Wm" id="1OShD0HTdS2" role="1ojpOf">
+                            <property role="TrG5h" value="bar" />
+                            <node concept="1oi5XN" id="1OShD0HTdS3" role="1oi5zu">
+                              <property role="1oi5yK" value="abc" />
+                            </node>
+                          </node>
+                        </node>
+                        <node concept="1oi5UN" id="1OShD0HTdS4" role="KCVpo">
+                          <node concept="1oi5Wm" id="1OShD0HTdS5" role="1ojpOf">
+                            <property role="TrG5h" value="qux" />
+                            <node concept="1oi5XN" id="1OShD0HTdS6" role="1oi5zu">
+                              <property role="1oi5yK" value="xyz" />
+                            </node>
                           </node>
                         </node>
                       </node>
-                      <node concept="1oi5UN" id="1OShD0HTdS4" role="KCVpo">
-                        <node concept="1oi5Wm" id="1OShD0HTdS5" role="1ojpOf">
-                          <property role="TrG5h" value="qux" />
-                          <node concept="1oi5XN" id="1OShD0HTdS6" role="1oi5zu">
-                            <property role="1oi5yK" value="xyz" />
-                          </node>
-                        </node>
+                    </node>
+                  </node>
+                </node>
+                <node concept="liA8E" id="3mz2_dYqXHW" role="2OqNvi">
+                  <ref role="37wK5l" to="oy3s:3mz2_dYqEdN" resolve="withMeta" />
+                  <node concept="2ShNRf" id="3mz2_dYqXJu" role="37wK5m">
+                    <node concept="1pGfFk" id="3mz2_dYqXYB" role="2ShVmc">
+                      <ref role="37wK5l" to="45ys:7nPD14NON$Y" resolve="MetaLogical" />
+                      <node concept="3VsKOn" id="3mz2_dYqY1N" role="37wK5m">
+                        <ref role="3VsUkX" to="ie8e:3OPtF03lco4" resolve="ListFunc" />
                       </node>
                     </node>
                   </node>
diff --git a/logic/solutions/jetbrains.mps.logic.test/models/jetbrains/mps/logic/test/unification.mps b/logic/solutions/jetbrains.mps.logic.test/models/jetbrains/mps/logic/test/unification.mps
index bd644860..e7308a36 100644
--- a/logic/solutions/jetbrains.mps.logic.test/models/jetbrains/mps/logic/test/unification.mps
+++ b/logic/solutions/jetbrains.mps.logic.test/models/jetbrains/mps/logic/test/unification.mps
@@ -94,6 +94,7 @@
       <concept id="1068580123165" name="jetbrains.mps.baseLanguage.structure.InstanceMethodDeclaration" flags="ig" index="3clFb_">
         <property id="1178608670077" name="isAbstract" index="1EzhhJ" />
       </concept>
+      <concept id="1068580123152" name="jetbrains.mps.baseLanguage.structure.EqualsExpression" flags="nn" index="3clFbC" />
       <concept id="1068580123155" name="jetbrains.mps.baseLanguage.structure.ExpressionStatement" flags="nn" index="3clFbF">
         <child id="1068580123156" name="expression" index="3clFbG" />
       </concept>
@@ -134,6 +135,10 @@
         <reference id="1107535924139" name="classifier" index="3uigEE" />
         <child id="1109201940907" name="parameter" index="11_B2D" />
       </concept>
+      <concept id="1081773326031" name="jetbrains.mps.baseLanguage.structure.BinaryOperation" flags="nn" index="3uHJSO">
+        <child id="1081773367579" name="rightExpression" index="3uHU7w" />
+        <child id="1081773367580" name="leftExpression" index="3uHU7B" />
+      </concept>
       <concept id="1178549954367" name="jetbrains.mps.baseLanguage.structure.IVisible" flags="ng" index="1B3ioH">
         <child id="1178549979242" name="visibility" index="1B3o_S" />
       </concept>
@@ -145,8 +150,14 @@
       </concept>
       <concept id="1146644602865" name="jetbrains.mps.baseLanguage.structure.PublicVisibility" flags="nn" index="3Tm1VV" />
       <concept id="1146644623116" name="jetbrains.mps.baseLanguage.structure.PrivateVisibility" flags="nn" index="3Tm6S6" />
+      <concept id="1116615150612" name="jetbrains.mps.baseLanguage.structure.ClassifierClassExpression" flags="nn" index="3VsKOn">
+        <reference id="1116615189566" name="classifier" index="3VsUkX" />
+      </concept>
     </language>
     <language id="f61473f9-130f-42f6-b98d-6c438812c2f6" name="jetbrains.mps.baseLanguage.unitTest">
+      <concept id="7080278351417106679" name="jetbrains.mps.baseLanguage.unitTest.structure.AssertInNotNull" flags="nn" index="2Hmddi">
+        <child id="7080278351417106681" name="expression" index="2Hmdds" />
+      </concept>
       <concept id="1171931690126" name="jetbrains.mps.baseLanguage.unitTest.structure.TestMethod" flags="ig" index="3s$Bmu">
         <property id="1171931690128" name="methodName" index="3s$Bm0" />
       </concept>
@@ -241,18 +252,30 @@
       <node concept="3clFbS" id="21Zu7ABuubZ" role="3clF47">
         <node concept="3clFbF" id="21Zu7ABuuuo" role="3cqZAp">
           <node concept="10QFUN" id="1OShD0I14HQ" role="3clFbG">
-            <node concept="2OqwBi" id="1OShD0I14HL" role="10QFUP">
-              <node concept="2ShNRf" id="1OShD0I14HM" role="2Oq$k0">
-                <node concept="1pGfFk" id="1OShD0I14HN" role="2ShVmc">
-                  <ref role="37wK5l" to="oy3s:1GDBwhEEL82" resolve="AtomLogical" />
-                  <node concept="37vLTw" id="1OShD0I14HO" role="37wK5m">
-                    <ref role="3cqZAo" node="21Zu7ABuute" resolve="name" />
+            <node concept="2YIFZM" id="3mz2_dYuDAz" role="10QFUP">
+              <ref role="37wK5l" to="yg8f:4TCblo5YI1H" resolve="asAtom" />
+              <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
+              <node concept="2OqwBi" id="3mz2_dYuJ$b" role="37wK5m">
+                <node concept="2ShNRf" id="1OShD0I14HM" role="2Oq$k0">
+                  <node concept="1pGfFk" id="1OShD0I14HN" role="2ShVmc">
+                    <ref role="37wK5l" to="oy3s:1GDBwhEEL82" resolve="AtomLogical" />
+                    <node concept="37vLTw" id="1OShD0I14HO" role="37wK5m">
+                      <ref role="3cqZAo" node="21Zu7ABuute" resolve="name" />
+                    </node>
+                    <node concept="10Nm6u" id="46l0wJhwVT1" role="37wK5m" />
+                  </node>
+                </node>
+                <node concept="liA8E" id="3mz2_dYuJLm" role="2OqNvi">
+                  <ref role="37wK5l" to="oy3s:3mz2_dYqEdN" resolve="withMeta" />
+                  <node concept="2ShNRf" id="3mz2_dYuJZn" role="37wK5m">
+                    <node concept="1pGfFk" id="3mz2_dYuKjv" role="2ShVmc">
+                      <ref role="37wK5l" to="45ys:7nPD14NON$Y" resolve="MetaLogical" />
+                      <node concept="3VsKOn" id="3mz2_dYuKxT" role="37wK5m">
+                        <ref role="3VsUkX" to="ie8e:5JQSuNswOXL" resolve="StemFunc" />
+                      </node>
+                    </node>
                   </node>
-                  <node concept="10Nm6u" id="46l0wJhwVT1" role="37wK5m" />
                 </node>
-              </node>
-              <node concept="liA8E" id="1OShD0I14HP" role="2OqNvi">
-                <ref role="37wK5l" to="oy3s:1Ns6gpY6DeD" resolve="asAtom" />
               </node>
             </node>
             <node concept="3uibUv" id="1OShD0I14Nx" role="10QFUM">
@@ -262,6 +285,53 @@
         </node>
       </node>
     </node>
+    <node concept="2tJIrI" id="3mz2_dYxUmw" role="jymVt" />
+    <node concept="3clFb_" id="3mz2_dYxTYD" role="jymVt">
+      <property role="TrG5h" value="listVar" />
+      <node concept="37vLTG" id="3mz2_dYxTYE" role="3clF46">
+        <property role="TrG5h" value="name" />
+        <node concept="17QB3L" id="3mz2_dYxTYF" role="1tU5fm" />
+      </node>
+      <node concept="3uibUv" id="3mz2_dYxTYG" role="3clF45">
+        <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+      </node>
+      <node concept="3Tm6S6" id="3mz2_dYxTYH" role="1B3o_S" />
+      <node concept="3clFbS" id="3mz2_dYxTYI" role="3clF47">
+        <node concept="3clFbF" id="3mz2_dYxTYJ" role="3cqZAp">
+          <node concept="10QFUN" id="3mz2_dYxTYK" role="3clFbG">
+            <node concept="2YIFZM" id="3mz2_dYxTYL" role="10QFUP">
+              <ref role="37wK5l" to="yg8f:4TCblo5YI1H" resolve="asAtom" />
+              <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
+              <node concept="2OqwBi" id="3mz2_dYxTYM" role="37wK5m">
+                <node concept="2ShNRf" id="3mz2_dYxTYN" role="2Oq$k0">
+                  <node concept="1pGfFk" id="3mz2_dYxTYO" role="2ShVmc">
+                    <ref role="37wK5l" to="oy3s:1GDBwhEEL82" resolve="AtomLogical" />
+                    <node concept="37vLTw" id="3mz2_dYxTYP" role="37wK5m">
+                      <ref role="3cqZAo" node="3mz2_dYxTYE" resolve="name" />
+                    </node>
+                    <node concept="10Nm6u" id="3mz2_dYxTYQ" role="37wK5m" />
+                  </node>
+                </node>
+                <node concept="liA8E" id="3mz2_dYxTYR" role="2OqNvi">
+                  <ref role="37wK5l" to="oy3s:3mz2_dYqEdN" resolve="withMeta" />
+                  <node concept="2ShNRf" id="3mz2_dYxTYS" role="37wK5m">
+                    <node concept="1pGfFk" id="3mz2_dYxTYT" role="2ShVmc">
+                      <ref role="37wK5l" to="45ys:7nPD14NON$Y" resolve="MetaLogical" />
+                      <node concept="3VsKOn" id="3mz2_dYxTYU" role="37wK5m">
+                        <ref role="3VsUkX" to="ie8e:3OPtF03lco4" resolve="ListFunc" />
+                      </node>
+                    </node>
+                  </node>
+                </node>
+              </node>
+            </node>
+            <node concept="3uibUv" id="3mz2_dYxTYV" role="10QFUM">
+              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
     <node concept="2tJIrI" id="5cGCTtqzpdN" role="jymVt" />
     <node concept="3clFb_" id="5cGCTtqzoJK" role="jymVt">
       <property role="TrG5h" value="wildcard" />
@@ -272,8 +342,13 @@
       <node concept="3clFbS" id="5cGCTtqzoJP" role="3clF47">
         <node concept="3clFbF" id="5cGCTtqzoJQ" role="3cqZAp">
           <node concept="10QFUN" id="5cGCTtqzoJR" role="3clFbG">
-            <node concept="2OqwBi" id="5cGCTtqzoJS" role="10QFUP">
-              <node concept="2ShNRf" id="5cGCTtqzoJT" role="2Oq$k0">
+            <node concept="3uibUv" id="5cGCTtqzoJY" role="10QFUM">
+              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+            </node>
+            <node concept="2YIFZM" id="3mz2_dYuDM0" role="10QFUP">
+              <ref role="37wK5l" to="yg8f:4TCblo5YI1H" resolve="asAtom" />
+              <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
+              <node concept="2ShNRf" id="5cGCTtqzoJT" role="37wK5m">
                 <node concept="1pGfFk" id="5cGCTtqzoJU" role="2ShVmc">
                   <ref role="37wK5l" to="oy3s:2DKqMqOlTiR" resolve="AtomLogical" />
                   <node concept="3clFbT" id="2DKqMqOmtXN" role="37wK5m">
@@ -281,12 +356,6 @@
                   </node>
                 </node>
               </node>
-              <node concept="liA8E" id="5cGCTtqzoJX" role="2OqNvi">
-                <ref role="37wK5l" to="oy3s:1Ns6gpY6DeD" resolve="asAtom" />
-              </node>
-            </node>
-            <node concept="3uibUv" id="5cGCTtqzoJY" role="10QFUM">
-              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
             </node>
           </node>
         </node>
@@ -1155,7 +1224,7 @@
                 <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
               </node>
               <node concept="1rXfSq" id="5_6ImQYXM88" role="33vP2m">
-                <ref role="37wK5l" node="21Zu7ABuubV" resolve="var" />
+                <ref role="37wK5l" node="3mz2_dYxTYD" resolve="listVar" />
                 <node concept="Xl_RD" id="5_6ImQYXM89" role="37wK5m">
                   <property role="Xl_RC" value="tail" />
                 </node>
@@ -1179,9 +1248,9 @@
                         </node>
                       </node>
                     </node>
-                    <node concept="1oi5UN" id="5_6ImQYXRqK" role="KCVpo">
-                      <node concept="22Ky0T" id="5_6ImQYXRqQ" role="lGtFl">
-                        <node concept="37vLTw" id="5_6ImQYXRsu" role="22Ky0K">
+                    <node concept="KCUsM" id="3mz2_dYxTSx" role="KCVpo">
+                      <node concept="22Ky0T" id="3mz2_dYxTSE" role="lGtFl">
+                        <node concept="37vLTw" id="3mz2_dYxTTb" role="22Ky0K">
                           <ref role="3cqZAo" node="5_6ImQYXM86" resolve="tail" />
                         </node>
                       </node>
@@ -1346,7 +1415,7 @@
                 <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
               </node>
               <node concept="1rXfSq" id="5_6ImQYY3rV" role="33vP2m">
-                <ref role="37wK5l" node="21Zu7ABuubV" resolve="var" />
+                <ref role="37wK5l" node="3mz2_dYxTYD" resolve="listVar" />
                 <node concept="Xl_RD" id="5_6ImQYY3rW" role="37wK5m">
                   <property role="Xl_RC" value="tail" />
                 </node>
@@ -1370,9 +1439,9 @@
                         </node>
                       </node>
                     </node>
-                    <node concept="1oi5UN" id="5_6ImQYY3s6" role="KCVpo">
-                      <node concept="22Ky0T" id="5_6ImQYY3s7" role="lGtFl">
-                        <node concept="37vLTw" id="5_6ImQYY3s8" role="22Ky0K">
+                    <node concept="KCUsM" id="3mz2_dYy0YN" role="KCVpo">
+                      <node concept="22Ky0T" id="3mz2_dYy0YW" role="lGtFl">
+                        <node concept="37vLTw" id="3mz2_dYy0Zw" role="22Ky0K">
                           <ref role="3cqZAo" node="5_6ImQYY3rT" resolve="tail" />
                         </node>
                       </node>
@@ -1654,8 +1723,10 @@
       <node concept="3clFbS" id="1OShD0Ifu8i" role="3clF47">
         <node concept="3clFbF" id="1OShD0Ifu8j" role="3cqZAp">
           <node concept="10QFUN" id="1OShD0Ifu8k" role="3clFbG">
-            <node concept="2OqwBi" id="1OShD0Ifu8l" role="10QFUP">
-              <node concept="2ShNRf" id="1OShD0Ifu8m" role="2Oq$k0">
+            <node concept="2YIFZM" id="3mz2_dYuEFA" role="10QFUP">
+              <ref role="37wK5l" to="yg8f:4TCblo5YI1H" resolve="asAtom" />
+              <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
+              <node concept="2ShNRf" id="1OShD0Ifu8m" role="37wK5m">
                 <node concept="1pGfFk" id="1OShD0Ifu8n" role="2ShVmc">
                   <ref role="37wK5l" to="oy3s:6SkxsM$96Z2" resolve="AtomLogical" />
                   <node concept="37vLTw" id="1OShD0Ifu8o" role="37wK5m">
@@ -1663,9 +1734,6 @@
                   </node>
                 </node>
               </node>
-              <node concept="liA8E" id="1OShD0Ifu8p" role="2OqNvi">
-                <ref role="37wK5l" to="oy3s:1Ns6gpY6DeD" resolve="asAtom" />
-              </node>
             </node>
             <node concept="3uibUv" id="1OShD0Ifu8q" role="10QFUM">
               <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
@@ -1684,8 +1752,13 @@
       <node concept="3clFbS" id="5cGCTtq$bC5" role="3clF47">
         <node concept="3clFbF" id="5cGCTtq$bC6" role="3cqZAp">
           <node concept="10QFUN" id="5cGCTtq$bC7" role="3clFbG">
-            <node concept="2OqwBi" id="5cGCTtq$bC8" role="10QFUP">
-              <node concept="2ShNRf" id="5cGCTtq$bC9" role="2Oq$k0">
+            <node concept="3uibUv" id="5cGCTtq$bCg" role="10QFUM">
+              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+            </node>
+            <node concept="2YIFZM" id="3mz2_dYuEPh" role="10QFUP">
+              <ref role="37wK5l" to="yg8f:4TCblo5YI1H" resolve="asAtom" />
+              <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
+              <node concept="2ShNRf" id="5cGCTtq$bC9" role="37wK5m">
                 <node concept="1pGfFk" id="5cGCTtq$bCa" role="2ShVmc">
                   <ref role="37wK5l" to="oy3s:2DKqMqOlTiR" resolve="AtomLogical" />
                   <node concept="3clFbT" id="2DKqMqOmrUu" role="37wK5m">
@@ -1693,12 +1766,6 @@
                   </node>
                 </node>
               </node>
-              <node concept="liA8E" id="5cGCTtq$bCf" role="2OqNvi">
-                <ref role="37wK5l" to="oy3s:1Ns6gpY6DeD" resolve="asAtom" />
-              </node>
-            </node>
-            <node concept="3uibUv" id="5cGCTtq$bCg" role="10QFUM">
-              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
             </node>
           </node>
         </node>
@@ -1714,8 +1781,13 @@
       <node concept="3clFbS" id="7nuzzkr25av" role="3clF47">
         <node concept="3clFbF" id="7nuzzkr25aw" role="3cqZAp">
           <node concept="10QFUN" id="7nuzzkr25ax" role="3clFbG">
-            <node concept="2OqwBi" id="7nuzzkr25ay" role="10QFUP">
-              <node concept="2ShNRf" id="7nuzzkr25az" role="2Oq$k0">
+            <node concept="3uibUv" id="7nuzzkr25aB" role="10QFUM">
+              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+            </node>
+            <node concept="2YIFZM" id="3mz2_dYuEZO" role="10QFUP">
+              <ref role="37wK5l" to="yg8f:4TCblo5YI1H" resolve="asAtom" />
+              <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
+              <node concept="2ShNRf" id="7nuzzkr25az" role="37wK5m">
                 <node concept="1pGfFk" id="7nuzzkr25a$" role="2ShVmc">
                   <ref role="37wK5l" to="oy3s:7nuzzkr2143" resolve="AtomLogical" />
                   <node concept="37vLTw" id="7nuzzkr26aF" role="37wK5m">
@@ -1726,12 +1798,6 @@
                   </node>
                 </node>
               </node>
-              <node concept="liA8E" id="7nuzzkr25aA" role="2OqNvi">
-                <ref role="37wK5l" to="oy3s:1Ns6gpY6DeD" resolve="asAtom" />
-              </node>
-            </node>
-            <node concept="3uibUv" id="7nuzzkr25aB" role="10QFUM">
-              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
             </node>
           </node>
         </node>
@@ -1751,30 +1817,25 @@
         </node>
       </node>
       <node concept="3uibUv" id="5p8T3QHH7gN" role="3clF45">
-        <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
+        <ref role="3uigEE" to="45ys:1mP5b6jQP$C" resolve="Logical" />
         <node concept="3qTvmN" id="5p8T3QHH7uW" role="11_B2D" />
       </node>
       <node concept="3Tm6S6" id="1OShD0IfFaJ" role="1B3o_S" />
       <node concept="3clFbS" id="1OShD0IfETn" role="3clF47">
-        <node concept="3clFbF" id="1OShD0IfFh0" role="3cqZAp">
-          <node concept="10QFUN" id="qubcdt9I3u" role="3clFbG">
-            <node concept="2OqwBi" id="qubcdt9I3o" role="10QFUP">
-              <node concept="1eOMI4" id="qubcdt9I3p" role="2Oq$k0">
-                <node concept="10QFUN" id="qubcdt9I3q" role="1eOMHV">
-                  <node concept="37vLTw" id="qubcdt9I3r" role="10QFUP">
-                    <ref role="3cqZAo" node="1OShD0IfFeh" resolve="var" />
-                  </node>
-                  <node concept="3uibUv" id="qubcdt9I3s" role="10QFUM">
-                    <ref role="3uigEE" to="yg8f:46l0wJhtOD_" resolve="ILogicalVar" />
-                  </node>
+        <node concept="3clFbF" id="3mz2_dYyGKT" role="3cqZAp">
+          <node concept="2OqwBi" id="qubcdt9I3o" role="3clFbG">
+            <node concept="1eOMI4" id="qubcdt9I3p" role="2Oq$k0">
+              <node concept="10QFUN" id="qubcdt9I3q" role="1eOMHV">
+                <node concept="37vLTw" id="qubcdt9I3r" role="10QFUP">
+                  <ref role="3cqZAo" node="1OShD0IfFeh" resolve="var" />
+                </node>
+                <node concept="3uibUv" id="qubcdt9I3s" role="10QFUM">
+                  <ref role="3uigEE" to="yg8f:46l0wJhtOD_" resolve="ILogicalVar" />
                 </node>
               </node>
-              <node concept="liA8E" id="qubcdt9I3t" role="2OqNvi">
-                <ref role="37wK5l" to="yg8f:46l0wJhtXlr" resolve="logical" />
-              </node>
             </node>
-            <node concept="3uibUv" id="qubcdt9I4K" role="10QFUM">
-              <ref role="3uigEE" to="yg8f:qubcdt1pkm" resolve="LogicalExt" />
+            <node concept="liA8E" id="qubcdt9I3t" role="2OqNvi">
+              <ref role="37wK5l" to="yg8f:46l0wJhtXlr" resolve="logical" />
             </node>
           </node>
         </node>
@@ -1909,7 +1970,7 @@
                 </node>
               </node>
               <node concept="liA8E" id="1OShD0IfIGc" role="2OqNvi">
-                <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
+                <ref role="37wK5l" to="45ys:dfChU1eNVy" resolve="findRoot" />
               </node>
             </node>
             <node concept="2OqwBi" id="1OShD0IfI6R" role="3tpDZB">
@@ -1920,7 +1981,7 @@
                 </node>
               </node>
               <node concept="liA8E" id="1OShD0IfIj2" role="2OqNvi">
-                <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
+                <ref role="37wK5l" to="45ys:dfChU1eNVy" resolve="findRoot" />
               </node>
             </node>
           </node>
@@ -2047,7 +2108,7 @@
                   </node>
                 </node>
                 <node concept="liA8E" id="3HJTsBn466m" role="2OqNvi">
-                  <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
+                  <ref role="37wK5l" to="45ys:dfChU1eNVy" resolve="findRoot" />
                 </node>
               </node>
               <node concept="liA8E" id="3HJTsBn466n" role="2OqNvi">
@@ -2256,7 +2317,7 @@
                   </node>
                 </node>
                 <node concept="liA8E" id="6MYr6Jy8m2W" role="2OqNvi">
-                  <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
+                  <ref role="37wK5l" to="45ys:dfChU1eNVy" resolve="findRoot" />
                 </node>
               </node>
               <node concept="liA8E" id="6MYr6Jy8m2X" role="2OqNvi">
@@ -2422,6 +2483,47 @@
               </node>
             </node>
           </node>
+          <node concept="3clFbH" id="3mz2_dYyyU1" role="3cqZAp" />
+          <node concept="2Hmddi" id="3mz2_dYyyKq" role="3cqZAp">
+            <node concept="2OqwBi" id="3mz2_dYyyKr" role="2Hmdds">
+              <node concept="37vLTw" id="3mz2_dYyyKs" role="2Oq$k0">
+                <ref role="3cqZAo" node="1OShD0IfO6H" resolve="x" />
+              </node>
+              <node concept="liA8E" id="3mz2_dYyyKt" role="2OqNvi">
+                <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
+              </node>
+            </node>
+          </node>
+          <node concept="2Hmddi" id="3mz2_dYyyKu" role="3cqZAp">
+            <node concept="2OqwBi" id="3mz2_dYyyKv" role="2Hmdds">
+              <node concept="37vLTw" id="3mz2_dYyyKw" role="2Oq$k0">
+                <ref role="3cqZAo" node="1OShD0IfP49" resolve="y" />
+              </node>
+              <node concept="liA8E" id="3mz2_dYyyKx" role="2OqNvi">
+                <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
+              </node>
+            </node>
+          </node>
+          <node concept="3vFxKo" id="3mz2_dYyyKy" role="3cqZAp">
+            <node concept="3clFbC" id="3mz2_dYyyKz" role="3vFALc">
+              <node concept="2OqwBi" id="3mz2_dYyyK$" role="3uHU7w">
+                <node concept="37vLTw" id="3mz2_dYyyK_" role="2Oq$k0">
+                  <ref role="3cqZAo" node="1OShD0IfP49" resolve="y" />
+                </node>
+                <node concept="liA8E" id="3mz2_dYyyKA" role="2OqNvi">
+                  <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
+                </node>
+              </node>
+              <node concept="2OqwBi" id="3mz2_dYyyKB" role="3uHU7B">
+                <node concept="37vLTw" id="3mz2_dYyyKC" role="2Oq$k0">
+                  <ref role="3cqZAo" node="1OShD0IfO6H" resolve="x" />
+                </node>
+                <node concept="liA8E" id="3mz2_dYyyKD" role="2OqNvi">
+                  <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
+                </node>
+              </node>
+            </node>
+          </node>
           <node concept="3clFbH" id="1OShD0IfOk1" role="3cqZAp" />
           <node concept="3clFbF" id="5jPBdKNGme" role="3cqZAp">
             <node concept="2OqwBi" id="5jPBdKNGmf" role="3clFbG">
@@ -2476,47 +2578,26 @@
             </node>
           </node>
           <node concept="3clFbH" id="1OShD0IfNCq" role="3cqZAp" />
-          <node concept="3vMLTj" id="1OShD0IfPnH" role="3cqZAp">
-            <node concept="2OqwBi" id="5cGCTtqzXdU" role="3tpDZA">
-              <node concept="2OqwBi" id="5cGCTtqzWGf" role="2Oq$k0">
-                <node concept="2OqwBi" id="1OShD0IfPnI" role="2Oq$k0">
-                  <node concept="1rXfSq" id="1OShD0IfPnJ" role="2Oq$k0">
-                    <ref role="37wK5l" node="1OShD0IfETi" resolve="asLogical" />
-                    <node concept="37vLTw" id="1OShD0IfPnK" role="37wK5m">
-                      <ref role="3cqZAo" node="1OShD0IfP49" resolve="y" />
-                    </node>
-                  </node>
-                  <node concept="liA8E" id="1OShD0IfPnL" role="2OqNvi">
-                    <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
-                  </node>
-                </node>
-                <node concept="liA8E" id="5cGCTtqzX8u" role="2OqNvi">
-                  <ref role="37wK5l" to="yg8f:7jC45Kci98e" resolve="asAtom" />
-                </node>
+          <node concept="3SKdUt" id="3mz2_dYyzc_" role="3cqZAp">
+            <node concept="3SKdUq" id="3mz2_dYyzcA" role="3SKWNk">
+              <property role="3SKdUp" value="testing that variables x and y are unified" />
+            </node>
+          </node>
+          <node concept="3vMLTj" id="3mz2_dYyzcB" role="3cqZAp">
+            <node concept="2OqwBi" id="3mz2_dYyzcC" role="3tpDZB">
+              <node concept="37vLTw" id="3mz2_dYyzcD" role="2Oq$k0">
+                <ref role="3cqZAo" node="1OShD0IfO6H" resolve="x" />
               </node>
-              <node concept="liA8E" id="5cGCTtqzXR9" role="2OqNvi">
-                <ref role="37wK5l" to="yt73:~Term.get():jetbrains.mps.unification.Term" resolve="get" />
+              <node concept="liA8E" id="3mz2_dYyzcE" role="2OqNvi">
+                <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
               </node>
             </node>
-            <node concept="2OqwBi" id="5cGCTtqzVZP" role="3tpDZB">
-              <node concept="2OqwBi" id="5cGCTtqzVEg" role="2Oq$k0">
-                <node concept="2OqwBi" id="1OShD0IfPnM" role="2Oq$k0">
-                  <node concept="1rXfSq" id="1OShD0IfPnN" role="2Oq$k0">
-                    <ref role="37wK5l" node="1OShD0IfETi" resolve="asLogical" />
-                    <node concept="37vLTw" id="1OShD0IfPnO" role="37wK5m">
-                      <ref role="3cqZAo" node="1OShD0IfO6H" resolve="x" />
-                    </node>
-                  </node>
-                  <node concept="liA8E" id="1OShD0IfPnP" role="2OqNvi">
-                    <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
-                  </node>
-                </node>
-                <node concept="liA8E" id="5cGCTtqzVUp" role="2OqNvi">
-                  <ref role="37wK5l" to="yg8f:7jC45Kci98e" resolve="asAtom" />
-                </node>
+            <node concept="2OqwBi" id="3mz2_dYyzcF" role="3tpDZA">
+              <node concept="37vLTw" id="3mz2_dYyzcG" role="2Oq$k0">
+                <ref role="3cqZAo" node="1OShD0IfP49" resolve="y" />
               </node>
-              <node concept="liA8E" id="5cGCTtqzWC9" role="2OqNvi">
-                <ref role="37wK5l" to="yt73:~Term.get():jetbrains.mps.unification.Term" resolve="get" />
+              <node concept="liA8E" id="3mz2_dYyzcH" role="2OqNvi">
+                <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
               </node>
             </node>
           </node>
@@ -2706,6 +2787,47 @@
             </node>
           </node>
           <node concept="3clFbH" id="5jPBdKNHr8" role="3cqZAp" />
+          <node concept="2Hmddi" id="3mz2_dYykZd" role="3cqZAp">
+            <node concept="2OqwBi" id="3mz2_dYyleq" role="2Hmdds">
+              <node concept="37vLTw" id="3mz2_dYyl7U" role="2Oq$k0">
+                <ref role="3cqZAo" node="4XqG8ivylRa" resolve="x" />
+              </node>
+              <node concept="liA8E" id="3mz2_dYylmd" role="2OqNvi">
+                <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
+              </node>
+            </node>
+          </node>
+          <node concept="2Hmddi" id="3mz2_dYylmy" role="3cqZAp">
+            <node concept="2OqwBi" id="3mz2_dYylmz" role="2Hmdds">
+              <node concept="37vLTw" id="3mz2_dYylvV" role="2Oq$k0">
+                <ref role="3cqZAo" node="4XqG8ivylRq" resolve="y" />
+              </node>
+              <node concept="liA8E" id="3mz2_dYylm_" role="2OqNvi">
+                <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
+              </node>
+            </node>
+          </node>
+          <node concept="3vFxKo" id="3mz2_dYytOw" role="3cqZAp">
+            <node concept="3clFbC" id="3mz2_dYyueD" role="3vFALc">
+              <node concept="2OqwBi" id="3mz2_dYyunv" role="3uHU7w">
+                <node concept="37vLTw" id="3mz2_dYyum8" role="2Oq$k0">
+                  <ref role="3cqZAo" node="4XqG8ivylRq" resolve="y" />
+                </node>
+                <node concept="liA8E" id="3mz2_dYyuoZ" role="2OqNvi">
+                  <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
+                </node>
+              </node>
+              <node concept="2OqwBi" id="3mz2_dYyu5J" role="3uHU7B">
+                <node concept="37vLTw" id="3mz2_dYytYr" role="2Oq$k0">
+                  <ref role="3cqZAo" node="4XqG8ivylRa" resolve="x" />
+                </node>
+                <node concept="liA8E" id="3mz2_dYyudo" role="2OqNvi">
+                  <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
+                </node>
+              </node>
+            </node>
+          </node>
+          <node concept="3clFbH" id="3mz2_dYytD$" role="3cqZAp" />
           <node concept="3clFbF" id="5jPBdKNHhT" role="3cqZAp">
             <node concept="2OqwBi" id="5jPBdKNHhU" role="3clFbG">
               <node concept="2OqwBi" id="5jPBdKNHhV" role="2Oq$k0">
@@ -2758,48 +2880,27 @@
               </node>
             </node>
           </node>
-          <node concept="3clFbH" id="4XqG8ivylRQ" role="3cqZAp" />
-          <node concept="3vMLTj" id="4XqG8ivylRR" role="3cqZAp">
-            <node concept="2OqwBi" id="5cGCTtq$6Np" role="3tpDZA">
-              <node concept="2OqwBi" id="5cGCTtq$6hS" role="2Oq$k0">
-                <node concept="2OqwBi" id="4XqG8ivylRS" role="2Oq$k0">
-                  <node concept="1rXfSq" id="4XqG8ivylRT" role="2Oq$k0">
-                    <ref role="37wK5l" node="1OShD0IfETi" resolve="asLogical" />
-                    <node concept="37vLTw" id="4XqG8ivylRU" role="37wK5m">
-                      <ref role="3cqZAo" node="4XqG8ivylRq" resolve="y" />
-                    </node>
-                  </node>
-                  <node concept="liA8E" id="4XqG8ivylRV" role="2OqNvi">
-                    <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
-                  </node>
-                </node>
-                <node concept="liA8E" id="5cGCTtq$6HX" role="2OqNvi">
-                  <ref role="37wK5l" to="yg8f:7jC45Kci98e" resolve="asAtom" />
-                </node>
+          <node concept="3clFbH" id="3mz2_dYyt5P" role="3cqZAp" />
+          <node concept="3SKdUt" id="3mz2_dYykGy" role="3cqZAp">
+            <node concept="3SKdUq" id="3mz2_dYykG$" role="3SKWNk">
+              <property role="3SKdUp" value="testing that variables x and y are unified" />
+            </node>
+          </node>
+          <node concept="3vMLTj" id="3mz2_dYylEJ" role="3cqZAp">
+            <node concept="2OqwBi" id="3mz2_dYylUZ" role="3tpDZB">
+              <node concept="37vLTw" id="3mz2_dYylO5" role="2Oq$k0">
+                <ref role="3cqZAo" node="4XqG8ivylRa" resolve="x" />
               </node>
-              <node concept="liA8E" id="5cGCTtq$7s_" role="2OqNvi">
-                <ref role="37wK5l" to="yt73:~Term.get():jetbrains.mps.unification.Term" resolve="get" />
+              <node concept="liA8E" id="3mz2_dYym2e" role="2OqNvi">
+                <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
               </node>
             </node>
-            <node concept="2OqwBi" id="5cGCTtq$5_x" role="3tpDZB">
-              <node concept="2OqwBi" id="5cGCTtq$4Ca" role="2Oq$k0">
-                <node concept="2OqwBi" id="4XqG8ivylRW" role="2Oq$k0">
-                  <node concept="1rXfSq" id="4XqG8ivylRX" role="2Oq$k0">
-                    <ref role="37wK5l" node="1OShD0IfETi" resolve="asLogical" />
-                    <node concept="37vLTw" id="4XqG8ivylRY" role="37wK5m">
-                      <ref role="3cqZAo" node="4XqG8ivylRa" resolve="x" />
-                    </node>
-                  </node>
-                  <node concept="liA8E" id="4XqG8ivylRZ" role="2OqNvi">
-                    <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
-                  </node>
-                </node>
-                <node concept="liA8E" id="5cGCTtq$5w5" role="2OqNvi">
-                  <ref role="37wK5l" to="yg8f:7jC45Kci98e" resolve="asAtom" />
-                </node>
+            <node concept="2OqwBi" id="3mz2_dYymac" role="3tpDZA">
+              <node concept="37vLTw" id="3mz2_dYym35" role="2Oq$k0">
+                <ref role="3cqZAo" node="4XqG8ivylRq" resolve="y" />
               </node>
-              <node concept="liA8E" id="5cGCTtq$6dM" role="2OqNvi">
-                <ref role="37wK5l" to="yt73:~Term.get():jetbrains.mps.unification.Term" resolve="get" />
+              <node concept="liA8E" id="3mz2_dYymhu" role="2OqNvi">
+                <ref role="37wK5l" to="ie8e:56MMu0Ark7v" resolve="get" />
               </node>
             </node>
           </node>
@@ -3897,8 +3998,13 @@
       <node concept="3clFbS" id="3K_0akS$LQp" role="3clF47">
         <node concept="3clFbF" id="3K_0akS$LQq" role="3cqZAp">
           <node concept="10QFUN" id="3K_0akS$LQr" role="3clFbG">
-            <node concept="2OqwBi" id="3K_0akS$LQs" role="10QFUP">
-              <node concept="2ShNRf" id="3K_0akS$LQt" role="2Oq$k0">
+            <node concept="3uibUv" id="3K_0akS$LQx" role="10QFUM">
+              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+            </node>
+            <node concept="2YIFZM" id="3mz2_dYuFY1" role="10QFUP">
+              <ref role="37wK5l" to="yg8f:4TCblo5YI1H" resolve="asAtom" />
+              <ref role="1Pybhc" to="yg8f:677NV565N1x" resolve="LogicalUtil" />
+              <node concept="2ShNRf" id="3K_0akS$LQt" role="37wK5m">
                 <node concept="1pGfFk" id="3K_0akS$LQu" role="2ShVmc">
                   <ref role="37wK5l" to="oy3s:6SkxsM$96Z2" resolve="AtomLogical" />
                   <node concept="37vLTw" id="3K_0akS$LQv" role="37wK5m">
@@ -3906,12 +4012,6 @@
                   </node>
                 </node>
               </node>
-              <node concept="liA8E" id="3K_0akS$LQw" role="2OqNvi">
-                <ref role="37wK5l" to="oy3s:1Ns6gpY6DeD" resolve="asAtom" />
-              </node>
-            </node>
-            <node concept="3uibUv" id="3K_0akS$LQx" role="10QFUM">
-              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
             </node>
           </node>
         </node>
@@ -4036,10 +4136,23 @@
               <node concept="3uibUv" id="3K_0akS$OxI" role="1tU5fm">
                 <ref role="3uigEE" to="oy3s:4U_yxogAknZ" resolve="AtomLogical" />
               </node>
-              <node concept="1rXfSq" id="3K_0akS$OxM" role="33vP2m">
-                <ref role="37wK5l" node="3K_0akS$NEa" resolve="logical" />
-                <node concept="Xl_RD" id="3K_0akS$OxN" role="37wK5m">
-                  <property role="Xl_RC" value="W1" />
+              <node concept="2OqwBi" id="3mz2_dYrb1a" role="33vP2m">
+                <node concept="1rXfSq" id="3K_0akS$OxM" role="2Oq$k0">
+                  <ref role="37wK5l" node="3K_0akS$NEa" resolve="logical" />
+                  <node concept="Xl_RD" id="3K_0akS$OxN" role="37wK5m">
+                    <property role="Xl_RC" value="W1" />
+                  </node>
+                </node>
+                <node concept="liA8E" id="3mz2_dYrbe2" role="2OqNvi">
+                  <ref role="37wK5l" to="oy3s:3mz2_dYqEdN" resolve="withMeta" />
+                  <node concept="2ShNRf" id="3mz2_dYrbhD" role="37wK5m">
+                    <node concept="1pGfFk" id="3mz2_dYrb$g" role="2ShVmc">
+                      <ref role="37wK5l" to="45ys:7nPD14NON$Y" resolve="MetaLogical" />
+                      <node concept="3VsKOn" id="3mz2_dYrbGJ" role="37wK5m">
+                        <ref role="3VsUkX" to="ie8e:5JQSuNswOXL" resolve="StemFunc" />
+                      </node>
+                    </node>
+                  </node>
                 </node>
               </node>
             </node>
@@ -4354,10 +4467,23 @@
               <node concept="3uibUv" id="3K_0akS_pD6" role="1tU5fm">
                 <ref role="3uigEE" to="oy3s:4U_yxogAknZ" resolve="AtomLogical" />
               </node>
-              <node concept="1rXfSq" id="3K_0akS_pD7" role="33vP2m">
-                <ref role="37wK5l" node="3K_0akS$NEa" resolve="logical" />
-                <node concept="Xl_RD" id="3K_0akS_pD8" role="37wK5m">
-                  <property role="Xl_RC" value="W1" />
+              <node concept="2OqwBi" id="3mz2_dYr7zp" role="33vP2m">
+                <node concept="1rXfSq" id="3K_0akS_pD7" role="2Oq$k0">
+                  <ref role="37wK5l" node="3K_0akS$NEa" resolve="logical" />
+                  <node concept="Xl_RD" id="3K_0akS_pD8" role="37wK5m">
+                    <property role="Xl_RC" value="W1" />
+                  </node>
+                </node>
+                <node concept="liA8E" id="3mz2_dYr7Kp" role="2OqNvi">
+                  <ref role="37wK5l" to="oy3s:3mz2_dYqEdN" resolve="withMeta" />
+                  <node concept="2ShNRf" id="3mz2_dYr7NZ" role="37wK5m">
+                    <node concept="1pGfFk" id="3mz2_dYr86A" role="2ShVmc">
+                      <ref role="37wK5l" to="45ys:7nPD14NON$Y" resolve="MetaLogical" />
+                      <node concept="3VsKOn" id="3mz2_dYr8bR" role="37wK5m">
+                        <ref role="3VsUkX" to="ie8e:5JQSuNswOXL" resolve="StemFunc" />
+                      </node>
+                    </node>
+                  </node>
                 </node>
               </node>
             </node>