diff --git a/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin/unification.mps b/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin/unification.mps
index 52b63acc..692bf578 100644
--- a/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin/unification.mps
+++ b/languages/jetbrains.mps.logic/runtime/models/jetbrains/mps/logic/builtin/unification.mps
@@ -3660,7 +3660,7 @@
         <ref role="2AI5Lk" to="e2lb:~Override" resolve="Override" />
       </node>
     </node>
-    <node concept="2tJIrI" id="1bm7a6ETr5E" role="jymVt" />
+    <node concept="2tJIrI" id="2h41Ezbxe8N" role="jymVt" />
     <node concept="312cEu" id="3HJTsBmSn3l" role="jymVt">
       <property role="TrG5h" value="TreeLogicalVar" />
       <property role="2bfB8j" value="true" />
@@ -3670,15 +3670,104 @@
         <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="3HJTsBmSn3s" role="3cqZAp">
+          <node concept="XkiVB" id="2h41EzbxxP9" role="3cqZAp">
             <ref role="37wK5l" to="ie8e:uNmovXiEVu" resolve="Variable" />
-            <node concept="1rXfSq" id="3HJTsBmTG8c" role="37wK5m">
-              <ref role="37wK5l" to="w2rx:~Logical.getName():java.lang.String" resolve="getName" />
+            <node concept="1rXfSq" id="2h41Ezbx$v8" role="37wK5m">
+              <ref role="37wK5l" node="3HJTsBmCy5P" resolve="name" />
             </node>
           </node>
         </node>
       </node>
-      <node concept="2tJIrI" id="3HJTsBmSn3E" role="jymVt" />
+      <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="2h41EzbwS8K" role="3clF45">
+          <ref role="3uigEE" to="jfki:~Node" resolve="Node" />
+        </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="1Ns6gpY6DeD" resolve="asTreePart" />
+                </node>
+              </node>
+            </node>
+            <node concept="1rXfSq" id="2h41EzbxGYR" role="3clFbw">
+              <ref role="37wK5l" node="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="e2lb:~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="2h41EzbwS8S" role="1tU5fm">
+            <ref role="3uigEE" to="jfki:~Node.Kind" resolve="Node.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="Rm8GQ" to="jfki:~Node.REF" resolve="REF" />
+                    <ref role="1Px2BO" to="jfki:~Node.Kind" resolve="Node.Kind" />
+                  </node>
+                </node>
+              </node>
+            </node>
+            <node concept="1rXfSq" id="2h41EzbxNuf" role="3clFbw">
+              <ref role="37wK5l" node="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="Rm8GQ" to="jfki:~Node.VAR" resolve="VAR" />
+                      <ref role="1Px2BO" to="jfki:~Node.Kind" resolve="Node.Kind" />
+                    </node>
+                  </node>
+                </node>
+              </node>
+            </node>
+          </node>
+        </node>
+        <node concept="2AHcQZ" id="2h41Ezbx7tm" role="2AJF6D">
+          <ref role="2AI5Lk" to="e2lb:~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">
@@ -3822,12 +3911,12 @@
         </node>
       </node>
       <node concept="2tJIrI" id="3HJTsBmSn4E" role="jymVt" />
-      <node concept="3uibUv" id="3HJTsBmSn4F" role="1zkMxy">
-        <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
-      </node>
       <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="2tJIrI" id="3HJTsBmSmpc" role="jymVt" />
     <node concept="3Tm1VV" id="4U_yxogAko0" role="1B3o_S" />
diff --git a/languages/jetbrains.mps.logic/test/models/jetbrains/mps/logic/test/logical.mps b/languages/jetbrains.mps.logic/test/models/jetbrains/mps/logic/test/logical.mps
index 89ddf6b9..25bd8f00 100644
--- a/languages/jetbrains.mps.logic/test/models/jetbrains/mps/logic/test/logical.mps
+++ b/languages/jetbrains.mps.logic/test/models/jetbrains/mps/logic/test/logical.mps
@@ -582,23 +582,6 @@
             </node>
           </node>
           <node concept="3clFbH" id="1OShD0HU_Ia" role="3cqZAp" />
-          <node concept="3cpWs8" id="1OShD0HU_Go" role="3cqZAp">
-            <node concept="3cpWsn" id="1OShD0HU_Gp" role="3cpWs9">
-              <property role="TrG5h" value="c" />
-              <node concept="3uibUv" id="1OShD0HU_Gq" role="1tU5fm">
-                <ref role="3uigEE" to="ie8e:2xQ7eRABXh4" resolve="Tree" />
-              </node>
-              <node concept="1oi1Uc" id="1OShD0HU_Gr" role="33vP2m">
-                <node concept="1oi5UN" id="1OShD0HU_Gs" role="1oi0x0">
-                  <node concept="1oi5ST" id="1OShD0HU_Gt" role="1ojpOf">
-                    <property role="TrG5h" value="foo" />
-                    <property role="1oi5Z2" value="single" />
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-          <node concept="3clFbH" id="1OShD0HUzFT" role="3cqZAp" />
           <node concept="3vlDli" id="1OShD0HUzFU" role="3cqZAp">
             <node concept="37vLTw" id="1OShD0HUzFV" role="3tpDZA">
               <ref role="3cqZAo" node="1OShD0HUzFO" resolve="b" />
@@ -607,14 +590,6 @@
               <ref role="3cqZAo" node="1OShD0HUzFH" resolve="a" />
             </node>
           </node>
-          <node concept="3vlDli" id="1OShD0HU_PH" role="3cqZAp">
-            <node concept="37vLTw" id="1OShD0HU_QC" role="3tpDZA">
-              <ref role="3cqZAo" node="1OShD0HU_Gp" resolve="c" />
-            </node>
-            <node concept="37vLTw" id="1OShD0HU_PJ" role="3tpDZB">
-              <ref role="3cqZAo" node="1OShD0HUzFH" resolve="a" />
-            </node>
-          </node>
         </node>
       </node>
     </node>
@@ -1480,7 +1455,6 @@
         <node concept="3cqZAl" id="2ev$9JFBKE9" role="3clF45" />
         <node concept="3Tm1VV" id="2ev$9JFBKEb" role="1B3o_S" />
         <node concept="3clFbS" id="2ev$9JFBKEc" role="3clF47">
-          <node concept="3clFbH" id="2ev$9JFDTUq" role="3cqZAp" />
           <node concept="3cpWs8" id="2ev$9JFBKEw" role="3cqZAp">
             <node concept="3cpWsn" id="2ev$9JFBKEx" role="3cpWs9">
               <property role="TrG5h" value="tree" />
@@ -1518,13 +1492,15 @@
                     <ref role="3cqZAo" node="2ev$9JFBNlS" resolve="mock" />
                   </node>
                   <node concept="liA8E" id="2ev$9JFD_nP" role="2OqNvi">
-                    <ref role="37wK5l" to="ie8e:3JgCwkqmHc0" resolve="walkList" />
+                    <ref role="37wK5l" to="ie8e:3JgCwkqiP3p" resolve="walkChild" />
                     <node concept="1rXfSq" id="2ev$9JFEITF" role="37wK5m">
-                      <ref role="37wK5l" node="2ev$9JFEHV1" resolve="anyList" />
+                      <ref role="37wK5l" node="2ev$9JFEEfC" resolve="anyChildren" />
                     </node>
                     <node concept="10QFUN" id="2ev$9JFD_pV" role="37wK5m">
-                      <node concept="3uibUv" id="2ev$9JFD_pW" role="10QFUM">
-                        <ref role="3uigEE" to="k7g3:~List" resolve="List" />
+                      <node concept="10Q1$e" id="5cGCTtqzbda" role="10QFUM">
+                        <node concept="3uibUv" id="5cGCTtqzaDx" role="10Q1$1">
+                          <ref role="3uigEE" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
+                        </node>
                       </node>
                       <node concept="2YIFZM" id="2ev$9JFD_pX" role="10QFUP">
                         <ref role="37wK5l" to="xxzj:~Matchers.anyObject():java.lang.Object" resolve="anyObject" />
@@ -1578,10 +1554,10 @@
                 </node>
               </node>
               <node concept="liA8E" id="2ev$9JFD93F" role="2OqNvi">
-                <ref role="37wK5l" to="ie8e:3JgCwkqmHc0" resolve="walkList" />
+                <ref role="37wK5l" to="ie8e:3JgCwkqiP3p" resolve="walkChild" />
                 <node concept="10QFUN" id="2ev$9JFDJDT" role="37wK5m">
-                  <node concept="3uibUv" id="2ev$9JFDJDN" role="10QFUM">
-                    <ref role="3uigEE" to="ie8e:3OPtF03lco4" resolve="ListBranch" />
+                  <node concept="3uibUv" id="5cGCTtqzhLw" role="10QFUM">
+                    <ref role="3uigEE" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
                   </node>
                   <node concept="2YIFZM" id="2ev$9JFDJDP" role="10QFUP">
                     <ref role="37wK5l" to="xxzj:~Matchers.eq(java.lang.Object):java.lang.Object" resolve="eq" />
@@ -1597,8 +1573,10 @@
                   </node>
                 </node>
                 <node concept="10QFUN" id="2ev$9JFD96P" role="37wK5m">
-                  <node concept="3uibUv" id="2ev$9JFD96Q" role="10QFUM">
-                    <ref role="3uigEE" to="k7g3:~List" resolve="List" />
+                  <node concept="10Q1$e" id="5cGCTtqzi2F" role="10QFUM">
+                    <node concept="3uibUv" id="5cGCTtqzhUK" role="10Q1$1">
+                      <ref role="3uigEE" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
+                    </node>
                   </node>
                   <node concept="2YIFZM" id="2ev$9JFD96R" role="10QFUP">
                     <ref role="37wK5l" to="xxzj:~Matchers.anyObject():java.lang.Object" resolve="anyObject" />
diff --git a/languages/jetbrains.mps.logic/test/models/jetbrains/mps/logic/test/unification.mps b/languages/jetbrains.mps.logic/test/models/jetbrains/mps/logic/test/unification.mps
index 42605004..edc908ed 100644
--- a/languages/jetbrains.mps.logic/test/models/jetbrains/mps/logic/test/unification.mps
+++ b/languages/jetbrains.mps.logic/test/models/jetbrains/mps/logic/test/unification.mps
@@ -70,6 +70,7 @@
       <concept id="1068580123137" name="jetbrains.mps.baseLanguage.structure.BooleanConstant" flags="nn" index="3clFbT">
         <property id="1068580123138" name="value" index="3clFbU" />
       </concept>
+      <concept id="1068581242875" name="jetbrains.mps.baseLanguage.structure.PlusExpression" flags="nn" index="3cpWs3" />
       <concept id="1068581242864" name="jetbrains.mps.baseLanguage.structure.LocalVariableDeclarationStatement" flags="nn" index="3cpWs8">
         <child id="1068581242865" name="localVariableDeclaration" index="3cpWs9" />
       </concept>
@@ -92,6 +93,10 @@
         <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>
@@ -219,6 +224,46 @@
         </node>
       </node>
     </node>
+    <node concept="2tJIrI" id="5cGCTtqzpdN" role="jymVt" />
+    <node concept="3clFb_" id="5cGCTtqzoJK" role="jymVt">
+      <property role="TrG5h" value="listVar" />
+      <node concept="37vLTG" id="5cGCTtqzoJL" role="3clF46">
+        <property role="TrG5h" value="name" />
+        <node concept="17QB3L" id="5cGCTtqzoJM" role="1tU5fm" />
+      </node>
+      <node concept="3uibUv" id="5cGCTtqzoJN" role="3clF45">
+        <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+      </node>
+      <node concept="3Tm6S6" id="5cGCTtqzoJO" role="1B3o_S" />
+      <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="1pGfFk" id="5cGCTtqzoJU" role="2ShVmc">
+                  <ref role="37wK5l" to="oy3s:1GDBwhEEL82" resolve="TreeLogical" />
+                  <node concept="3cpWs3" id="5cGCTtqzpZa" role="37wK5m">
+                    <node concept="Xl_RD" id="5cGCTtqzq15" role="3uHU7B">
+                      <property role="Xl_RC" value="_" />
+                    </node>
+                    <node concept="37vLTw" id="5cGCTtqzoJV" role="3uHU7w">
+                      <ref role="3cqZAo" node="5cGCTtqzoJL" resolve="name" />
+                    </node>
+                  </node>
+                  <node concept="10Nm6u" id="5cGCTtqzoJW" role="37wK5m" />
+                </node>
+              </node>
+              <node concept="liA8E" id="5cGCTtqzoJX" role="2OqNvi">
+                <ref role="37wK5l" to="oy3s:1Ns6gpY6DeD" resolve="asTreePart" />
+              </node>
+            </node>
+            <node concept="3uibUv" id="5cGCTtqzoJY" role="10QFUM">
+              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
     <node concept="2tJIrI" id="46l0wJhwUVT" role="jymVt" />
     <node concept="3clFb_" id="46l0wJhwUlm" role="jymVt">
       <property role="TrG5h" value="stringVar" />
@@ -890,7 +935,7 @@
                       <node concept="1oi5UN" id="677NV56y2bw" role="KCVpo">
                         <node concept="22Ky0T" id="677NV56y2bx" role="lGtFl">
                           <node concept="1rXfSq" id="1OShD0I1vDw" role="22Ky0K">
-                            <ref role="37wK5l" node="21Zu7ABuubV" resolve="treeVar" />
+                            <ref role="37wK5l" node="5cGCTtqzoJK" resolve="listVar" />
                             <node concept="Xl_RD" id="1OShD0I1vDx" role="37wK5m">
                               <property role="Xl_RC" value="X" />
                             </node>
@@ -972,7 +1017,7 @@
                       <node concept="1oi5UN" id="677NV56y2bC" role="KCVpo">
                         <node concept="22Ky0T" id="677NV56y2bD" role="lGtFl">
                           <node concept="1rXfSq" id="1OShD0If5v6" role="22Ky0K">
-                            <ref role="37wK5l" node="21Zu7ABuubV" resolve="treeVar" />
+                            <ref role="37wK5l" node="5cGCTtqzoJK" resolve="listVar" />
                             <node concept="Xl_RD" id="1OShD0If5v7" role="37wK5m">
                               <property role="Xl_RC" value="X" />
                             </node>
@@ -1109,6 +1154,46 @@
         </node>
       </node>
     </node>
+    <node concept="2tJIrI" id="5cGCTtq$bBZ" role="jymVt" />
+    <node concept="3clFb_" id="5cGCTtq$bC0" role="jymVt">
+      <property role="TrG5h" value="listVar" />
+      <node concept="37vLTG" id="5cGCTtq$bC1" role="3clF46">
+        <property role="TrG5h" value="name" />
+        <node concept="17QB3L" id="5cGCTtq$bC2" role="1tU5fm" />
+      </node>
+      <node concept="3uibUv" id="5cGCTtq$bC3" role="3clF45">
+        <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+      </node>
+      <node concept="3Tm6S6" id="5cGCTtq$bC4" role="1B3o_S" />
+      <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="1pGfFk" id="5cGCTtq$bCa" role="2ShVmc">
+                  <ref role="37wK5l" to="oy3s:1GDBwhEEL82" resolve="TreeLogical" />
+                  <node concept="3cpWs3" id="5cGCTtq$bCb" role="37wK5m">
+                    <node concept="Xl_RD" id="5cGCTtq$bCc" role="3uHU7B">
+                      <property role="Xl_RC" value="_" />
+                    </node>
+                    <node concept="37vLTw" id="5cGCTtq$bCd" role="3uHU7w">
+                      <ref role="3cqZAo" node="5cGCTtq$bC1" resolve="name" />
+                    </node>
+                  </node>
+                  <node concept="10Nm6u" id="5cGCTtq$bCe" role="37wK5m" />
+                </node>
+              </node>
+              <node concept="liA8E" id="5cGCTtq$bCf" role="2OqNvi">
+                <ref role="37wK5l" to="oy3s:1Ns6gpY6DeD" resolve="asTreePart" />
+              </node>
+            </node>
+            <node concept="3uibUv" id="5cGCTtq$bCg" role="10QFUM">
+              <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
     <node concept="2tJIrI" id="3HJTsBn43rK" role="jymVt" />
     <node concept="3clFb_" id="3HJTsBn41DA" role="jymVt">
       <property role="TrG5h" value="stringVar" />
@@ -1815,26 +1900,46 @@
           </node>
           <node concept="3clFbH" id="1OShD0IfNCq" role="3cqZAp" />
           <node concept="3vMLTj" id="1OShD0IfPnH" role="3cqZAp">
-            <node concept="2OqwBi" id="1OShD0IfPnI" role="3tpDZA">
-              <node concept="1rXfSq" id="1OShD0IfPnJ" role="2Oq$k0">
-                <ref role="37wK5l" node="1OShD0IfETi" resolve="asLogical" />
-                <node concept="37vLTw" id="1OShD0IfPnK" role="37wK5m">
-                  <ref role="3cqZAo" node="1OShD0IfP49" resolve="y" />
+            <node concept="2OqwBi" id="5cGCTtqzXdU" role="3tpDZA">
+              <node concept="2OqwBi" id="5cGCTtqzWGf" role="2Oq$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="asTreePart" />
                 </node>
               </node>
-              <node concept="liA8E" id="1OShD0IfPnL" role="2OqNvi">
-                <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
+              <node concept="liA8E" id="5cGCTtqzXR9" role="2OqNvi">
+                <ref role="37wK5l" to="jfki:~Node.get()" resolve="get" />
               </node>
             </node>
-            <node concept="2OqwBi" id="1OShD0IfPnM" role="3tpDZB">
-              <node concept="1rXfSq" id="1OShD0IfPnN" role="2Oq$k0">
-                <ref role="37wK5l" node="1OShD0IfETi" resolve="asLogical" />
-                <node concept="37vLTw" id="1OShD0IfPnO" role="37wK5m">
-                  <ref role="3cqZAo" node="1OShD0IfO6H" resolve="x" />
+            <node concept="2OqwBi" id="5cGCTtqzVZP" role="3tpDZB">
+              <node concept="2OqwBi" id="5cGCTtqzVEg" role="2Oq$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="asTreePart" />
                 </node>
               </node>
-              <node concept="liA8E" id="1OShD0IfPnP" role="2OqNvi">
-                <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
+              <node concept="liA8E" id="5cGCTtqzWC9" role="2OqNvi">
+                <ref role="37wK5l" to="jfki:~Node.get()" resolve="get" />
               </node>
             </node>
           </node>
@@ -2051,26 +2156,46 @@
           </node>
           <node concept="3clFbH" id="4XqG8ivylRQ" role="3cqZAp" />
           <node concept="3vMLTj" id="4XqG8ivylRR" role="3cqZAp">
-            <node concept="2OqwBi" id="4XqG8ivylRS" role="3tpDZA">
-              <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 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="asTreePart" />
                 </node>
               </node>
-              <node concept="liA8E" id="4XqG8ivylRV" role="2OqNvi">
-                <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
+              <node concept="liA8E" id="5cGCTtq$7s_" role="2OqNvi">
+                <ref role="37wK5l" to="jfki:~Node.get()" resolve="get" />
               </node>
             </node>
-            <node concept="2OqwBi" id="4XqG8ivylRW" role="3tpDZB">
-              <node concept="1rXfSq" id="4XqG8ivylRX" role="2Oq$k0">
-                <ref role="37wK5l" node="1OShD0IfETi" resolve="asLogical" />
-                <node concept="37vLTw" id="4XqG8ivylRY" role="37wK5m">
-                  <ref role="3cqZAo" node="4XqG8ivylRa" resolve="x" />
+            <node 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="asTreePart" />
                 </node>
               </node>
-              <node concept="liA8E" id="4XqG8ivylRZ" role="2OqNvi">
-                <ref role="37wK5l" to="yg8f:dfChU1eNVy" resolve="findRoot" />
+              <node concept="liA8E" id="5cGCTtq$6dM" role="2OqNvi">
+                <ref role="37wK5l" to="jfki:~Node.get()" resolve="get" />
               </node>
             </node>
           </node>
@@ -2572,7 +2697,7 @@
                 <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
               </node>
               <node concept="1rXfSq" id="1OShD0Ig2iP" role="33vP2m">
-                <ref role="37wK5l" node="1OShD0Ifu8d" resolve="treeVar" />
+                <ref role="37wK5l" node="5cGCTtq$bC0" resolve="listVar" />
                 <node concept="Xl_RD" id="1OShD0Ig2iQ" role="37wK5m">
                   <property role="Xl_RC" value="X" />
                 </node>
@@ -2638,7 +2763,7 @@
           <node concept="3clFbH" id="1OShD0IgaFL" role="3cqZAp" />
           <node concept="3SKdUt" id="1OShD0IgaFJ" role="3cqZAp">
             <node concept="3SKdUq" id="1OShD0IgaFK" role="3SKWNk">
-              <property role="3SKdUp" value="variable in the last position matches the _list_" />
+              <property role="3SKdUp" value="*list* variable in the last position matches the _list_" />
             </node>
           </node>
           <node concept="3clFbH" id="1OShD0IgaFw" role="3cqZAp" />
@@ -2728,7 +2853,7 @@
                 <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
               </node>
               <node concept="1rXfSq" id="1OShD0IgaBW" role="33vP2m">
-                <ref role="37wK5l" node="1OShD0Ifu8d" resolve="treeVar" />
+                <ref role="37wK5l" node="5cGCTtq$bC0" resolve="listVar" />
                 <node concept="Xl_RD" id="1OShD0IgaBX" role="37wK5m">
                   <property role="Xl_RC" value="X" />
                 </node>
@@ -2802,7 +2927,7 @@
           <node concept="3clFbH" id="1OShD0Ig2jc" role="3cqZAp" />
           <node concept="3SKdUt" id="1OShD0Ig7rm" role="3cqZAp">
             <node concept="3SKdUq" id="1OShD0Ig7vG" role="3SKWNk">
-              <property role="3SKdUp" value="variable in the last position matches the _list_" />
+              <property role="3SKdUp" value="*list* variable in the last position matches the _list_" />
             </node>
           </node>
           <node concept="3clFbH" id="1OShD0Ig2jr" role="3cqZAp" />
@@ -2866,7 +2991,7 @@
                 <ref role="3uigEE" to="ie8e:uNmovXiEd4" resolve="Variable" />
               </node>
               <node concept="1rXfSq" id="1OShD0IgiMe" role="33vP2m">
-                <ref role="37wK5l" node="1OShD0Ifu8d" resolve="treeVar" />
+                <ref role="37wK5l" node="5cGCTtq$bC0" resolve="listVar" />
                 <node concept="Xl_RD" id="1OShD0IgiMf" role="37wK5m">
                   <property role="Xl_RC" value="X" />
                 </node>
@@ -2924,7 +3049,7 @@
           <node concept="3clFbH" id="1OShD0IgiRL" role="3cqZAp" />
           <node concept="3SKdUt" id="1OShD0IgiRM" role="3cqZAp">
             <node concept="3SKdUq" id="1OShD0IgiRN" role="3SKWNk">
-              <property role="3SKdUp" value="variable in the last position matches the _list_" />
+              <property role="3SKdUp" value="*list* variable in the last position matches the _list_" />
             </node>
           </node>
           <node concept="3clFbH" id="1OShD0IgiRZ" role="3cqZAp" />
diff --git a/solutions/jetbrains.mps.unification.tree/models/jetbrains/mps/unification/tree.mps b/solutions/jetbrains.mps.unification.tree/models/jetbrains/mps/unification/tree.mps
index 6ba996b2..1520c670 100644
--- a/solutions/jetbrains.mps.unification.tree/models/jetbrains/mps/unification/tree.mps
+++ b/solutions/jetbrains.mps.unification.tree/models/jetbrains/mps/unification/tree.mps
@@ -160,7 +160,7 @@
         <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" index="3clFbS">
+      <concept id="1068580123136" name="jetbrains.mps.baseLanguage.structure.StatementList" flags="sn" stub="5293379017992965193" index="3clFbS">
         <child id="1068581517665" name="statement" index="3cqZAp" />
       </concept>
       <concept id="1068580123137" name="jetbrains.mps.baseLanguage.structure.BooleanConstant" flags="nn" index="3clFbT">
@@ -404,13 +404,7 @@
       <node concept="3clFbS" id="5JQSuNs_vzW" role="3clF47">
         <node concept="3clFbF" id="5JQSuNs_vCE" role="3cqZAp">
           <node concept="3cpWs3" id="5JQSuNs_w4o" role="3clFbG">
-            <node concept="Xl_RD" id="5JQSuNs_w4y" role="3uHU7w">
-              <property role="Xl_RC" value="]" />
-            </node>
             <node concept="3cpWs3" id="5JQSuNs_vHV" role="3uHU7B">
-              <node concept="Xl_RD" id="5JQSuNs_vCD" role="3uHU7B">
-                <property role="Xl_RC" value="[" />
-              </node>
               <node concept="2YIFZM" id="5JQSuNs_vOU" role="3uHU7w">
                 <ref role="37wK5l" to="e2lb:~String.valueOf(java.lang.Object):java.lang.String" resolve="valueOf" />
                 <ref role="1Pybhc" to="e2lb:~String" resolve="String" />
@@ -418,6 +412,12 @@
                   <ref role="3cqZAo" node="5JQSuNsxMAD" resolve="root" />
                 </node>
               </node>
+              <node concept="Xl_RD" id="5cGCTtq$xeT" role="3uHU7B">
+                <property role="Xl_RC" value="{" />
+              </node>
+            </node>
+            <node concept="Xl_RD" id="5cGCTtq$x5C" role="3uHU7w">
+              <property role="Xl_RC" value="}" />
             </node>
           </node>
         </node>
@@ -9628,6 +9628,70 @@
         <node concept="10Oyi0" id="3OPtF03lcoS" role="1tU5fm" />
       </node>
       <node concept="3clFbS" id="3OPtF03lcoT" role="3clF47">
+        <node concept="3clFbJ" id="5cGCTtqwF$s" role="3cqZAp">
+          <node concept="3clFbS" id="5cGCTtqwF$u" role="3clFbx">
+            <node concept="3SKdUt" id="5cGCTtqwSKB" role="3cqZAp">
+              <node concept="3SKdUq" id="5cGCTtqwSN9" role="3SKWNk">
+                <property role="3SKdUp" value="special case: list is passed directly" />
+              </node>
+            </node>
+            <node concept="3cpWs6" id="5cGCTtqwSTO" role="3cqZAp">
+              <node concept="10QFUN" id="5cGCTtqwU3b" role="3cqZAk">
+                <node concept="3uibUv" id="5cGCTtqwU38" role="10QFUM">
+                  <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
+                  <node concept="16syzq" id="5cGCTtqwU39" role="11_B2D">
+                    <ref role="16sUi3" node="3OPtF03lcq9" resolve="T" />
+                  </node>
+                </node>
+                <node concept="AH0OO" id="5cGCTtqwZBu" role="10QFUP">
+                  <node concept="3cmrfG" id="5cGCTtqx046" role="AHEQo">
+                    <property role="3cmrfH" value="0" />
+                  </node>
+                  <node concept="37vLTw" id="5cGCTtqwVt3" role="AHHXb">
+                    <ref role="3cqZAo" node="3OPtF03lcoO" resolve="elements" />
+                  </node>
+                </node>
+              </node>
+            </node>
+          </node>
+          <node concept="1Wc70l" id="5cGCTtqwPf4" role="3clFbw">
+            <node concept="2ZW3vV" id="5cGCTtqwRCJ" role="3uHU7w">
+              <node concept="3uibUv" id="5cGCTtqwRM6" role="2ZW6by">
+                <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
+              </node>
+              <node concept="AH0OO" id="5cGCTtqwQpn" role="2ZW6bz">
+                <node concept="3cmrfG" id="5cGCTtqwQxI" role="AHEQo">
+                  <property role="3cmrfH" value="0" />
+                </node>
+                <node concept="37vLTw" id="5cGCTtqwPBw" role="AHHXb">
+                  <ref role="3cqZAo" node="3OPtF03lcoO" resolve="elements" />
+                </node>
+              </node>
+            </node>
+            <node concept="1Wc70l" id="5cGCTtqwKSF" role="3uHU7B">
+              <node concept="3clFbC" id="5cGCTtqwJHu" role="3uHU7B">
+                <node concept="37vLTw" id="5cGCTtqwIxE" role="3uHU7B">
+                  <ref role="3cqZAo" node="3OPtF03lcoR" resolve="headIdx" />
+                </node>
+                <node concept="3cmrfG" id="5cGCTtqwKEf" role="3uHU7w">
+                  <property role="3cmrfH" value="0" />
+                </node>
+              </node>
+              <node concept="3clFbC" id="5cGCTtqwOXM" role="3uHU7w">
+                <node concept="2OqwBi" id="5cGCTtqwM1R" role="3uHU7B">
+                  <node concept="37vLTw" id="5cGCTtqwLRj" role="2Oq$k0">
+                    <ref role="3cqZAo" node="3OPtF03lcoO" resolve="elements" />
+                  </node>
+                  <node concept="1Rwk04" id="5cGCTtqwNhE" role="2OqNvi" />
+                </node>
+                <node concept="3cmrfG" id="5cGCTtqwOZw" role="3uHU7w">
+                  <property role="3cmrfH" value="1" />
+                </node>
+              </node>
+            </node>
+          </node>
+        </node>
+        <node concept="3clFbH" id="5cGCTtqwNhH" role="3cqZAp" />
         <node concept="3clFbJ" id="3OPtF03lcoU" role="3cqZAp">
           <node concept="3clFbS" id="3OPtF03lcoV" role="3clFbx">
             <node concept="3cpWs8" id="3OPtF03lcoW" role="3cqZAp">
@@ -10258,16 +10322,8 @@
         <node concept="3clFbF" id="2q_78a92HDg" role="3cqZAp">
           <node concept="2OqwBi" id="2q_78a92HDh" role="3clFbG">
             <node concept="2OqwBi" id="2q_78a92HDi" role="2Oq$k0">
-              <node concept="2OqwBi" id="2q_78a92K68" role="2Oq$k0">
-                <node concept="37vLTw" id="2q_78a92HDj" role="2Oq$k0">
-                  <ref role="3cqZAo" node="2q_78a92HDc" resolve="sb" />
-                </node>
-                <node concept="liA8E" id="2q_78a92LKn" role="2OqNvi">
-                  <ref role="37wK5l" to="e2lb:~StringBuilder.append(java.lang.String):java.lang.StringBuilder" resolve="append" />
-                  <node concept="Xl_RD" id="2q_78a92N88" role="37wK5m">
-                    <property role="Xl_RC" value="\&quot;" />
-                  </node>
-                </node>
+              <node concept="37vLTw" id="2q_78a92HDj" role="2Oq$k0">
+                <ref role="3cqZAo" node="2q_78a92HDc" resolve="sb" />
               </node>
               <node concept="liA8E" id="2q_78a92HDk" role="2OqNvi">
                 <ref role="37wK5l" to="e2lb:~StringBuilder.append(java.lang.String):java.lang.StringBuilder" resolve="append" />
@@ -10283,7 +10339,7 @@
             <node concept="liA8E" id="2q_78a92HDp" role="2OqNvi">
               <ref role="37wK5l" to="e2lb:~StringBuilder.append(java.lang.String):java.lang.StringBuilder" resolve="append" />
               <node concept="Xl_RD" id="2q_78a92HDq" role="37wK5m">
-                <property role="Xl_RC" value="\&quot;=[" />
+                <property role="Xl_RC" value="=[" />
               </node>
             </node>
           </node>