From 77479a076fae86d5ebf07b9e1a0de2746cfa39be Mon Sep 17 00:00:00 2001
From: Fedor Isakov <fisakov@gmail.com>
Date: Tue, 24 Mar 2015 16:24:56 +0100
Subject: [PATCH] Support for variables matching a list, getting rid of
 obsolete code, some refactoring

---
 .../mps/lang/typesystem2/runtime/template.mps | 102 ++--
 .../generator/template/main@generator.mps     | 350 ++++++++-----
 .../models/jetbrains/mps/logic/sandbox.mps    | 458 +----------------
 .../mps/typechecking/handler/producer.mps     |   4 +-
 .../models/jetbrains/mps/unification/tree.mps | 476 ++++--------------
 5 files changed, 380 insertions(+), 1010 deletions(-)

diff --git a/languages/jetbrains.mps.lang.typesystem2/runtime/models/jetbrains/mps/lang/typesystem2/runtime/template.mps b/languages/jetbrains.mps.lang.typesystem2/runtime/models/jetbrains/mps/lang/typesystem2/runtime/template.mps
index ba9b0251..e026ce01 100644
--- a/languages/jetbrains.mps.lang.typesystem2/runtime/models/jetbrains/mps/lang/typesystem2/runtime/template.mps
+++ b/languages/jetbrains.mps.lang.typesystem2/runtime/models/jetbrains/mps/lang/typesystem2/runtime/template.mps
@@ -451,20 +451,20 @@
       <node concept="3clFbS" id="6YyAPwCTFsH" role="3clF47">
         <node concept="3clFbJ" id="6YyAPwCTFsI" role="3cqZAp">
           <node concept="3clFbS" id="6YyAPwCTFsJ" role="3clFbx">
-            <node concept="3cpWs6" id="6YyAPwCVMeb" role="3cqZAp">
-              <node concept="2YIFZM" id="6YyAPwCVNEK" role="3cqZAk">
-                <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-                <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                <node concept="Xl_RD" id="6YyAPwCVNEL" role="37wK5m">
+            <node concept="3cpWs6" id="6SZa6nhEj0C" role="3cqZAp">
+              <node concept="2YIFZM" id="6SZa6nhEnaU" role="3cqZAk">
+                <ref role="37wK5l" to="ie8e:5JQSuNsxhfn" resolve="create" />
+                <ref role="1Pybhc" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
+                <node concept="Xl_RD" id="6SZa6nhEqtd" role="37wK5m">
                   <property role="Xl_RC" value="node" />
                 </node>
-                <node concept="2YIFZM" id="6YyAPwCVNEM" role="37wK5m">
+                <node concept="2YIFZM" id="6SZa6nhEqte" role="37wK5m">
                   <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
                   <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                  <node concept="Xl_RD" id="6YyAPwCVNEN" role="37wK5m">
+                  <node concept="Xl_RD" id="6SZa6nhEqtf" role="37wK5m">
                     <property role="Xl_RC" value="node" />
                   </node>
-                  <node concept="Xl_RD" id="6YyAPwCVNEO" role="37wK5m">
+                  <node concept="Xl_RD" id="6SZa6nhEqtg" role="37wK5m">
                     <property role="Xl_RC" value="null" />
                   </node>
                 </node>
@@ -540,40 +540,40 @@
                 </node>
               </node>
             </node>
-            <node concept="3cpWs6" id="6YyAPwCVPe9" role="3cqZAp">
-              <node concept="2YIFZM" id="6YyAPwCVQ$E" role="3cqZAk">
-                <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-                <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                <node concept="Xl_RD" id="6YyAPwCVQ$F" role="37wK5m">
+            <node concept="3cpWs6" id="6SZa6nhEwLh" role="3cqZAp">
+              <node concept="2YIFZM" id="6SZa6nhE$vH" role="3cqZAk">
+                <ref role="37wK5l" to="ie8e:5JQSuNsxhfn" resolve="create" />
+                <ref role="1Pybhc" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
+                <node concept="Xl_RD" id="6SZa6nhE_Mh" role="37wK5m">
                   <property role="Xl_RC" value="node" />
                 </node>
-                <node concept="2YIFZM" id="6YyAPwCVQ$G" role="37wK5m">
-                  <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
+                <node concept="2YIFZM" id="6SZa6nhE_Mi" role="37wK5m">
                   <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                  <node concept="Xl_RD" id="6YyAPwCVQ$H" role="37wK5m">
+                  <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
+                  <node concept="Xl_RD" id="6SZa6nhE_Mj" role="37wK5m">
                     <property role="Xl_RC" value="concept" />
                   </node>
-                  <node concept="37vLTw" id="6YyAPwCVQ$I" role="37wK5m">
+                  <node concept="37vLTw" id="6SZa6nhE_Mk" role="37wK5m">
                     <ref role="3cqZAo" node="6YyAPwCTFsW" resolve="cpt" />
                   </node>
                 </node>
-                <node concept="2YIFZM" id="6YyAPwCVQ$J" role="37wK5m">
+                <node concept="2YIFZM" id="6SZa6nhE_Ml" role="37wK5m">
                   <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
                   <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
-                  <node concept="Xl_RD" id="6YyAPwCVQ$K" role="37wK5m">
+                  <node concept="Xl_RD" id="6SZa6nhE_Mm" role="37wK5m">
                     <property role="Xl_RC" value="name" />
                   </node>
-                  <node concept="37vLTw" id="6YyAPwCVQ$L" role="37wK5m">
+                  <node concept="37vLTw" id="6SZa6nhE_Mn" role="37wK5m">
                     <ref role="3cqZAo" node="6YyAPwCTFtg" resolve="name" />
                   </node>
                 </node>
-                <node concept="2YIFZM" id="6YyAPwCVQ$M" role="37wK5m">
-                  <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
+                <node concept="2YIFZM" id="6SZa6nhE_Mo" role="37wK5m">
                   <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                  <node concept="Xl_RD" id="6YyAPwCVQ$N" role="37wK5m">
+                  <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
+                  <node concept="Xl_RD" id="6SZa6nhE_Mp" role="37wK5m">
                     <property role="Xl_RC" value="id" />
                   </node>
-                  <node concept="37vLTw" id="6YyAPwCVQ$O" role="37wK5m">
+                  <node concept="37vLTw" id="6SZa6nhE_Mq" role="37wK5m">
                     <ref role="3cqZAo" node="6YyAPwCTFt5" resolve="id" />
                   </node>
                 </node>
@@ -631,40 +631,40 @@
             <ref role="3cqZAo" node="6YyAPwCTFtD" resolve="text" />
           </node>
           <node concept="3clFbS" id="6YyAPwCTFtU" role="2tyzPh">
-            <node concept="3cpWs6" id="6YyAPwCVS1s" role="3cqZAp">
-              <node concept="2YIFZM" id="6YyAPwCVTne" role="3cqZAk">
-                <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-                <node concept="Xl_RD" id="6YyAPwCVTnf" role="37wK5m">
+            <node concept="3cpWs6" id="6SZa6nhEGUW" role="3cqZAp">
+              <node concept="2YIFZM" id="6SZa6nhEJrM" role="3cqZAk">
+                <ref role="37wK5l" to="ie8e:5JQSuNsxhfn" resolve="create" />
+                <ref role="1Pybhc" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
+                <node concept="Xl_RD" id="6SZa6nhEKIU" role="37wK5m">
                   <property role="Xl_RC" value="node" />
                 </node>
-                <node concept="2YIFZM" id="6YyAPwCVTng" role="37wK5m">
-                  <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
+                <node concept="2YIFZM" id="6SZa6nhEKIV" role="37wK5m">
                   <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                  <node concept="Xl_RD" id="6YyAPwCVTnh" role="37wK5m">
+                  <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
+                  <node concept="Xl_RD" id="6SZa6nhEKIW" role="37wK5m">
                     <property role="Xl_RC" value="concept" />
                   </node>
-                  <node concept="37vLTw" id="6YyAPwCVTni" role="37wK5m">
+                  <node concept="37vLTw" id="6SZa6nhEKIX" role="37wK5m">
                     <ref role="3cqZAo" node="6YyAPwCTFsW" resolve="cpt" />
                   </node>
                 </node>
-                <node concept="2YIFZM" id="6YyAPwCVTnj" role="37wK5m">
+                <node concept="2YIFZM" id="6SZa6nhEKIY" role="37wK5m">
                   <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
                   <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
-                  <node concept="Xl_RD" id="6YyAPwCVTnk" role="37wK5m">
+                  <node concept="Xl_RD" id="6SZa6nhEKIZ" role="37wK5m">
                     <property role="Xl_RC" value="text" />
                   </node>
-                  <node concept="1TxZTf" id="6YyAPwCVTnl" role="37wK5m">
+                  <node concept="1TxZTf" id="6SZa6nhEKJ0" role="37wK5m">
                     <ref role="1Ty1U8" node="6YyAPwCTFtO" resolve="ascii" />
                   </node>
                 </node>
-                <node concept="2YIFZM" id="6YyAPwCVTnm" role="37wK5m">
+                <node concept="2YIFZM" id="6SZa6nhEKJ1" role="37wK5m">
                   <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
                   <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
-                  <node concept="Xl_RD" id="6YyAPwCVTnn" role="37wK5m">
+                  <node concept="Xl_RD" id="6SZa6nhEKJ2" role="37wK5m">
                     <property role="Xl_RC" value="id" />
                   </node>
-                  <node concept="37vLTw" id="6YyAPwCVTno" role="37wK5m">
+                  <node concept="37vLTw" id="6SZa6nhEKJ3" role="37wK5m">
                     <ref role="3cqZAo" node="6YyAPwCTFt5" resolve="id" />
                   </node>
                 </node>
@@ -673,30 +673,30 @@
           </node>
         </node>
         <node concept="3clFbH" id="6YyAPwCTFu8" role="3cqZAp" />
-        <node concept="3cpWs6" id="6YyAPwCVUNT" role="3cqZAp">
-          <node concept="2YIFZM" id="6YyAPwCVWaO" role="3cqZAk">
-            <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-            <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-            <node concept="Xl_RD" id="6YyAPwCVWaP" role="37wK5m">
+        <node concept="3cpWs6" id="6SZa6nhEOZF" role="3cqZAp">
+          <node concept="2YIFZM" id="6SZa6nhESO9" role="3cqZAk">
+            <ref role="37wK5l" to="ie8e:5JQSuNsxhfn" resolve="create" />
+            <ref role="1Pybhc" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
+            <node concept="Xl_RD" id="6SZa6nhEU7V" role="37wK5m">
               <property role="Xl_RC" value="node" />
             </node>
-            <node concept="2YIFZM" id="6YyAPwCVWaQ" role="37wK5m">
+            <node concept="2YIFZM" id="6SZa6nhEU7W" role="37wK5m">
               <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
               <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-              <node concept="Xl_RD" id="6YyAPwCVWaR" role="37wK5m">
+              <node concept="Xl_RD" id="6SZa6nhEU7X" role="37wK5m">
                 <property role="Xl_RC" value="concept" />
               </node>
-              <node concept="37vLTw" id="6YyAPwCVWaS" role="37wK5m">
+              <node concept="37vLTw" id="6SZa6nhEU7Y" role="37wK5m">
                 <ref role="3cqZAo" node="6YyAPwCTFsW" resolve="cpt" />
               </node>
             </node>
-            <node concept="2YIFZM" id="6YyAPwCVWaT" role="37wK5m">
-              <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
+            <node concept="2YIFZM" id="6SZa6nhEU7Z" role="37wK5m">
               <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-              <node concept="Xl_RD" id="6YyAPwCVWaU" role="37wK5m">
+              <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
+              <node concept="Xl_RD" id="6SZa6nhEU80" role="37wK5m">
                 <property role="Xl_RC" value="id" />
               </node>
-              <node concept="37vLTw" id="6YyAPwCVWaV" role="37wK5m">
+              <node concept="37vLTw" id="6SZa6nhEU81" role="37wK5m">
                 <ref role="3cqZAo" node="6YyAPwCTFt5" resolve="id" />
               </node>
             </node>
diff --git a/languages/jetbrains.mps.logic/generator/template/main@generator.mps b/languages/jetbrains.mps.logic/generator/template/main@generator.mps
index 75f1cd49..8fe88509 100644
--- a/languages/jetbrains.mps.logic/generator/template/main@generator.mps
+++ b/languages/jetbrains.mps.logic/generator/template/main@generator.mps
@@ -297,6 +297,7 @@
         <child id="1145404616321" name="leftExpression" index="2JrQYb" />
       </concept>
       <concept id="1171305280644" name="jetbrains.mps.lang.smodel.structure.Node_GetDescendantsOperation" flags="nn" index="2Rf3mk" />
+      <concept id="1171310072040" name="jetbrains.mps.lang.smodel.structure.Node_GetContainingRootOperation" flags="nn" index="2Rxl7S" />
       <concept id="1171407110247" name="jetbrains.mps.lang.smodel.structure.Node_GetAncestorOperation" flags="nn" index="2Xjw5R" />
       <concept id="1154546920561" name="jetbrains.mps.lang.smodel.structure.OperationParm_ConceptList" flags="ng" index="3gmYPX">
         <child id="1154546920563" name="concept" index="3gmYPZ" />
@@ -572,7 +573,29 @@
             <node concept="2ShNRf" id="2q_78a9qcCp" role="1eOMHV">
               <node concept="1pGfFk" id="2q_78a9qcOd" role="2ShVmc">
                 <ref role="37wK5l" to="oy3s:1GDBwhEEL82" resolve="TreeLogical" />
-                <node concept="10Nm6u" id="2q_78a9qcQ2" role="37wK5m" />
+                <node concept="Xl_RD" id="6SZa6nhPTCr" role="37wK5m">
+                  <property role="Xl_RC" value="_" />
+                  <node concept="17Uvod" id="6SZa6nhPTEY" role="lGtFl">
+                    <property role="P4ACc" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1070475926800/1070475926801" />
+                    <property role="2qtEX9" value="value" />
+                    <node concept="3zFVjK" id="6SZa6nhPTEZ" role="3zH0cK">
+                      <node concept="3clFbS" id="6SZa6nhPTF0" role="2VODD2">
+                        <node concept="3clFbF" id="6SZa6nhPU7n" role="3cqZAp">
+                          <node concept="2OqwBi" id="6SZa6nhPU$i" role="3clFbG">
+                            <node concept="1iwH7S" id="6SZa6nhPUuQ" role="2Oq$k0" />
+                            <node concept="2piZGk" id="6SZa6nhPUKr" role="2OqNvi">
+                              <node concept="3zGtF$" id="6SZa6nhPV2t" role="2piZGb" />
+                              <node concept="2OqwBi" id="6SZa6nhPVwH" role="2pr8EU">
+                                <node concept="30H73N" id="6SZa6nhPVsc" role="2Oq$k0" />
+                                <node concept="2Rxl7S" id="6SZa6nhPVVl" role="2OqNvi" />
+                              </node>
+                            </node>
+                          </node>
+                        </node>
+                      </node>
+                    </node>
+                  </node>
+                </node>
                 <node concept="10Nm6u" id="2q_78a9qcWL" role="37wK5m" />
               </node>
             </node>
@@ -828,26 +851,26 @@
   <node concept="13MO4I" id="35Lj3TiT1Wl">
     <property role="TrG5h" value="Ast_Builder" />
     <ref role="3gUMe" to="5j4j:6$jH9oLmUCq" resolve="Ast" />
-    <node concept="2YIFZM" id="35Lj3TiT3ic" role="13RCb5">
-      <ref role="37wK5l" to="ie8e:5JQSuNsxMa3" resolve="tree" />
-      <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-      <node concept="10Nm6u" id="35Lj3TiT3id" role="37wK5m">
-        <node concept="29HgVG" id="35Lj3TiT3ie" role="lGtFl">
-          <node concept="3NFfHV" id="35Lj3TiT3if" role="3NFExx">
-            <node concept="3clFbS" id="35Lj3TiT3ig" role="2VODD2">
-              <node concept="3clFbF" id="35Lj3TiT3ih" role="3cqZAp">
-                <node concept="2OqwBi" id="35Lj3TiT3ii" role="3clFbG">
-                  <node concept="3TrEf2" id="35Lj3TiT3ij" role="2OqNvi">
+    <node concept="2YIFZM" id="6SZa6nhFws5" role="13RCb5">
+      <ref role="37wK5l" to="ie8e:5JQSuNsxMzt" resolve="create" />
+      <ref role="1Pybhc" to="ie8e:2xQ7eRABXh4" resolve="Tree" />
+      <node concept="10Nm6u" id="6SZa6nhFws6" role="37wK5m">
+        <node concept="29HgVG" id="6SZa6nhFws7" role="lGtFl">
+          <node concept="3NFfHV" id="6SZa6nhFws8" role="3NFExx">
+            <node concept="3clFbS" id="6SZa6nhFws9" role="2VODD2">
+              <node concept="3clFbF" id="6SZa6nhFwsa" role="3cqZAp">
+                <node concept="2OqwBi" id="6SZa6nhFwsb" role="3clFbG">
+                  <node concept="3TrEf2" id="6SZa6nhFwsc" role="2OqNvi">
                     <ref role="3Tt5mk" to="5j4j:6$jH9oLmVNm" />
                   </node>
-                  <node concept="30H73N" id="35Lj3TiT3ik" role="2Oq$k0" />
+                  <node concept="30H73N" id="6SZa6nhFwsd" role="2Oq$k0" />
                 </node>
               </node>
             </node>
           </node>
         </node>
       </node>
-      <node concept="raruj" id="35Lj3TiT5EM" role="lGtFl" />
+      <node concept="raruj" id="6SZa6nhFwse" role="lGtFl" />
     </node>
   </node>
   <node concept="bUwia" id="7E86$tKtJwT">
@@ -1474,46 +1497,44 @@
         </node>
       </node>
       <node concept="14YyZ8" id="1OShD0H$xo0" role="1lVwrX">
-        <node concept="14ZrTv" id="1OShD0H$xo1" role="14ZwWg">
-          <node concept="30G5F_" id="1OShD0H$xo2" role="150hEN">
-            <node concept="3clFbS" id="1OShD0H$xo3" role="2VODD2">
-              <node concept="3clFbF" id="1OShD0H$xo4" role="3cqZAp">
-                <node concept="3fqX7Q" id="1OShD0H$xo5" role="3clFbG">
-                  <node concept="2OqwBi" id="1OShD0H$xo6" role="3fr31v">
-                    <node concept="2OqwBi" id="1OShD0H$xo7" role="2Oq$k0">
-                      <node concept="2OqwBi" id="1OShD0H$xo8" role="2Oq$k0">
-                        <node concept="30H73N" id="1OShD0H$xo9" role="2Oq$k0" />
-                        <node concept="3Tsc0h" id="1OShD0H$xoa" role="2OqNvi">
-                          <ref role="3TtcxE" to="5j4j:6$jH9oLmYFB" />
-                        </node>
+        <node concept="14ZrTv" id="6SZa6nhLXnf" role="14ZwWg">
+          <node concept="30G5F_" id="6SZa6nhLXng" role="150hEN">
+            <node concept="3clFbS" id="6SZa6nhLXnh" role="2VODD2">
+              <node concept="3clFbF" id="6SZa6nhLXIg" role="3cqZAp">
+                <node concept="2OqwBi" id="6SZa6nhM2CJ" role="3clFbG">
+                  <node concept="2OqwBi" id="6SZa6nhLZ98" role="2Oq$k0">
+                    <node concept="2OqwBi" id="6SZa6nhLXNt" role="2Oq$k0">
+                      <node concept="30H73N" id="6SZa6nhLXIf" role="2Oq$k0" />
+                      <node concept="3Tsc0h" id="6SZa6nhLYhW" role="2OqNvi">
+                        <ref role="3TtcxE" to="5j4j:6$jH9oLmYFB" />
                       </node>
-                      <node concept="1uHKPH" id="1OShD0H$xob" role="2OqNvi" />
                     </node>
-                    <node concept="1mIQ4w" id="1OShD0H$xoc" role="2OqNvi">
-                      <node concept="chp4Y" id="1OShD0H$xod" role="cj9EA">
-                        <ref role="cht4Q" to="5j4j:6SkxsM$4k7r" resolve="AbstractVariable" />
-                      </node>
+                    <node concept="1uHKPH" id="6SZa6nhM1s5" role="2OqNvi" />
+                  </node>
+                  <node concept="1mIQ4w" id="6SZa6nhM3ht" role="2OqNvi">
+                    <node concept="chp4Y" id="6SZa6nhM3o7" role="cj9EA">
+                      <ref role="cht4Q" to="5j4j:1OShD0HAY6y" resolve="ListNode" />
                     </node>
                   </node>
                 </node>
               </node>
             </node>
           </node>
-          <node concept="gft3U" id="1OShD0H$xoe" role="150oIE">
-            <node concept="2YIFZM" id="1OShD0H$xof" role="gfFT$">
-              <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-              <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-              <node concept="Xl_RD" id="1OShD0H$xog" role="37wK5m">
+          <node concept="gft3U" id="6SZa6nhM3Jq" role="150oIE">
+            <node concept="2YIFZM" id="6SZa6nhM3Jr" role="gfFT$">
+              <ref role="1Pybhc" to="ie8e:3OPtF03lco4" resolve="ListBranch" />
+              <ref role="37wK5l" to="ie8e:3OPtF03lcom" resolve="create" />
+              <node concept="Xl_RD" id="6SZa6nhM3Js" role="37wK5m">
                 <property role="Xl_RC" value="name" />
-                <node concept="17Uvod" id="1OShD0H$xoh" role="lGtFl">
+                <node concept="17Uvod" id="6SZa6nhM3Jt" role="lGtFl">
                   <property role="2qtEX9" value="value" />
                   <property role="P4ACc" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1070475926800/1070475926801" />
-                  <node concept="3zFVjK" id="1OShD0H$xoi" role="3zH0cK">
-                    <node concept="3clFbS" id="1OShD0H$xoj" role="2VODD2">
-                      <node concept="3clFbF" id="1OShD0H$xok" role="3cqZAp">
-                        <node concept="2OqwBi" id="1OShD0H$xol" role="3clFbG">
-                          <node concept="30H73N" id="1OShD0H$xom" role="2Oq$k0" />
-                          <node concept="3TrcHB" id="1OShD0H$xon" role="2OqNvi">
+                  <node concept="3zFVjK" id="6SZa6nhM3Ju" role="3zH0cK">
+                    <node concept="3clFbS" id="6SZa6nhM3Jv" role="2VODD2">
+                      <node concept="3clFbF" id="6SZa6nhM3Jw" role="3cqZAp">
+                        <node concept="2OqwBi" id="6SZa6nhM3Jx" role="3clFbG">
+                          <node concept="30H73N" id="6SZa6nhM3Jy" role="2Oq$k0" />
+                          <node concept="3TrcHB" id="6SZa6nhM3Jz" role="2OqNvi">
                             <ref role="3TsBF5" to="tpck:h0TrG11" resolve="name" />
                           </node>
                         </node>
@@ -1522,16 +1543,16 @@
                   </node>
                 </node>
               </node>
-              <node concept="10Nm6u" id="1OShD0H$xoo" role="37wK5m">
-                <node concept="2b32R4" id="1OShD0H$xop" role="lGtFl">
-                  <node concept="3JmXsc" id="1OShD0H$xoq" role="2P8S$">
-                    <node concept="3clFbS" id="1OShD0H$xor" role="2VODD2">
-                      <node concept="3clFbF" id="1OShD0H$xos" role="3cqZAp">
-                        <node concept="2OqwBi" id="1OShD0H$xot" role="3clFbG">
-                          <node concept="3Tsc0h" id="1OShD0H$xou" role="2OqNvi">
+              <node concept="10Nm6u" id="6SZa6nhM3J$" role="37wK5m">
+                <node concept="2b32R4" id="6SZa6nhM3J_" role="lGtFl">
+                  <node concept="3JmXsc" id="6SZa6nhM3JA" role="2P8S$">
+                    <node concept="3clFbS" id="6SZa6nhM3JB" role="2VODD2">
+                      <node concept="3clFbF" id="6SZa6nhM3JC" role="3cqZAp">
+                        <node concept="2OqwBi" id="6SZa6nhM3JD" role="3clFbG">
+                          <node concept="3Tsc0h" id="6SZa6nhM3JE" role="2OqNvi">
                             <ref role="3TtcxE" to="5j4j:6$jH9oLmYFB" />
                           </node>
-                          <node concept="30H73N" id="1OShD0H$xov" role="2Oq$k0" />
+                          <node concept="30H73N" id="6SZa6nhM3JF" role="2Oq$k0" />
                         </node>
                       </node>
                     </node>
@@ -1541,21 +1562,86 @@
             </node>
           </node>
         </node>
-        <node concept="gft3U" id="1OShD0H$xow" role="14YRTM">
-          <node concept="2YIFZM" id="1OShD0H$xox" role="gfFT$">
-            <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-            <ref role="37wK5l" to="ie8e:uNmovXjpCg" resolve="variable" />
-            <node concept="Xl_RD" id="1OShD0H$xoy" role="37wK5m">
+        <node concept="14ZrTv" id="6SZa6nhMXnU" role="14ZwWg">
+          <node concept="30G5F_" id="6SZa6nhMXnV" role="150hEN">
+            <node concept="3clFbS" id="6SZa6nhMXnW" role="2VODD2">
+              <node concept="3clFbF" id="6SZa6nhMXP0" role="3cqZAp">
+                <node concept="2OqwBi" id="6SZa6nhMXP2" role="3clFbG">
+                  <node concept="2OqwBi" id="6SZa6nhMXP3" role="2Oq$k0">
+                    <node concept="2OqwBi" id="6SZa6nhMXP4" role="2Oq$k0">
+                      <node concept="30H73N" id="6SZa6nhMXP5" role="2Oq$k0" />
+                      <node concept="3Tsc0h" id="6SZa6nhMXP6" role="2OqNvi">
+                        <ref role="3TtcxE" to="5j4j:6$jH9oLmYFB" />
+                      </node>
+                    </node>
+                    <node concept="1uHKPH" id="6SZa6nhMXP7" role="2OqNvi" />
+                  </node>
+                  <node concept="1mIQ4w" id="6SZa6nhMXP8" role="2OqNvi">
+                    <node concept="chp4Y" id="6SZa6nhMXP9" role="cj9EA">
+                      <ref role="cht4Q" to="5j4j:6SkxsM$4k7r" resolve="AbstractVariable" />
+                    </node>
+                  </node>
+                </node>
+              </node>
+            </node>
+          </node>
+          <node concept="gft3U" id="1OShD0H$xow" role="150oIE">
+            <node concept="2YIFZM" id="1OShD0H$xox" role="gfFT$">
+              <ref role="37wK5l" to="ie8e:uNmovXjpCg" resolve="variable" />
+              <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
+              <node concept="Xl_RD" id="1OShD0H$xoy" role="37wK5m">
+                <property role="Xl_RC" value="name" />
+                <node concept="17Uvod" id="1OShD0H$xoz" role="lGtFl">
+                  <property role="2qtEX9" value="value" />
+                  <property role="P4ACc" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1070475926800/1070475926801" />
+                  <node concept="3zFVjK" id="1OShD0H$xo$" role="3zH0cK">
+                    <node concept="3clFbS" id="1OShD0H$xo_" role="2VODD2">
+                      <node concept="3clFbF" id="1OShD0H$xoA" role="3cqZAp">
+                        <node concept="2OqwBi" id="1OShD0H$xoB" role="3clFbG">
+                          <node concept="30H73N" id="1OShD0H$xoC" role="2Oq$k0" />
+                          <node concept="3TrcHB" id="1OShD0H$xoD" role="2OqNvi">
+                            <ref role="3TsBF5" to="tpck:h0TrG11" resolve="name" />
+                          </node>
+                        </node>
+                      </node>
+                    </node>
+                  </node>
+                </node>
+              </node>
+              <node concept="10Nm6u" id="1OShD0H$xoE" role="37wK5m">
+                <node concept="2b32R4" id="1OShD0H$xoF" role="lGtFl">
+                  <node concept="3JmXsc" id="1OShD0H$xoG" role="2P8S$">
+                    <node concept="3clFbS" id="1OShD0H$xoH" role="2VODD2">
+                      <node concept="3clFbF" id="1OShD0H$xoI" role="3cqZAp">
+                        <node concept="2OqwBi" id="1OShD0H$xoJ" role="3clFbG">
+                          <node concept="3Tsc0h" id="1OShD0H$xoK" role="2OqNvi">
+                            <ref role="3TtcxE" to="5j4j:6$jH9oLmYFB" />
+                          </node>
+                          <node concept="30H73N" id="1OShD0H$xoL" role="2Oq$k0" />
+                        </node>
+                      </node>
+                    </node>
+                  </node>
+                </node>
+              </node>
+            </node>
+          </node>
+        </node>
+        <node concept="gft3U" id="6SZa6nhMYH7" role="14YRTM">
+          <node concept="2YIFZM" id="6SZa6nhMYH8" role="gfFT$">
+            <ref role="1Pybhc" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
+            <ref role="37wK5l" to="ie8e:5JQSuNsxhfn" resolve="create" />
+            <node concept="Xl_RD" id="6SZa6nhMYH9" role="37wK5m">
               <property role="Xl_RC" value="name" />
-              <node concept="17Uvod" id="1OShD0H$xoz" role="lGtFl">
+              <node concept="17Uvod" id="6SZa6nhMYHa" role="lGtFl">
                 <property role="2qtEX9" value="value" />
                 <property role="P4ACc" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1070475926800/1070475926801" />
-                <node concept="3zFVjK" id="1OShD0H$xo$" role="3zH0cK">
-                  <node concept="3clFbS" id="1OShD0H$xo_" role="2VODD2">
-                    <node concept="3clFbF" id="1OShD0H$xoA" role="3cqZAp">
-                      <node concept="2OqwBi" id="1OShD0H$xoB" role="3clFbG">
-                        <node concept="30H73N" id="1OShD0H$xoC" role="2Oq$k0" />
-                        <node concept="3TrcHB" id="1OShD0H$xoD" role="2OqNvi">
+                <node concept="3zFVjK" id="6SZa6nhMYHb" role="3zH0cK">
+                  <node concept="3clFbS" id="6SZa6nhMYHc" role="2VODD2">
+                    <node concept="3clFbF" id="6SZa6nhMYHd" role="3cqZAp">
+                      <node concept="2OqwBi" id="6SZa6nhMYHe" role="3clFbG">
+                        <node concept="30H73N" id="6SZa6nhMYHf" role="2Oq$k0" />
+                        <node concept="3TrcHB" id="6SZa6nhMYHg" role="2OqNvi">
                           <ref role="3TsBF5" to="tpck:h0TrG11" resolve="name" />
                         </node>
                       </node>
@@ -1564,16 +1650,16 @@
                 </node>
               </node>
             </node>
-            <node concept="10Nm6u" id="1OShD0H$xoE" role="37wK5m">
-              <node concept="2b32R4" id="1OShD0H$xoF" role="lGtFl">
-                <node concept="3JmXsc" id="1OShD0H$xoG" role="2P8S$">
-                  <node concept="3clFbS" id="1OShD0H$xoH" role="2VODD2">
-                    <node concept="3clFbF" id="1OShD0H$xoI" role="3cqZAp">
-                      <node concept="2OqwBi" id="1OShD0H$xoJ" role="3clFbG">
-                        <node concept="3Tsc0h" id="1OShD0H$xoK" role="2OqNvi">
+            <node concept="10Nm6u" id="6SZa6nhMYHh" role="37wK5m">
+              <node concept="2b32R4" id="6SZa6nhMYHi" role="lGtFl">
+                <node concept="3JmXsc" id="6SZa6nhMYHj" role="2P8S$">
+                  <node concept="3clFbS" id="6SZa6nhMYHk" role="2VODD2">
+                    <node concept="3clFbF" id="6SZa6nhMYHl" role="3cqZAp">
+                      <node concept="2OqwBi" id="6SZa6nhMYHm" role="3clFbG">
+                        <node concept="3Tsc0h" id="6SZa6nhMYHn" role="2OqNvi">
                           <ref role="3TtcxE" to="5j4j:6$jH9oLmYFB" />
                         </node>
-                        <node concept="30H73N" id="1OShD0H$xoL" role="2Oq$k0" />
+                        <node concept="30H73N" id="6SZa6nhMYHo" role="2Oq$k0" />
                       </node>
                     </node>
                   </node>
@@ -1607,20 +1693,20 @@
         </node>
       </node>
       <node concept="gft3U" id="1OShD0H$B7w" role="1lVwrX">
-        <node concept="2YIFZM" id="1OShD0H$B7x" role="gfFT$">
-          <ref role="37wK5l" to="ie8e:6$jH9oLaYQA" resolve="childrenList" />
-          <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-          <node concept="Xl_RD" id="1OShD0H$B7y" role="37wK5m">
+        <node concept="2YIFZM" id="6SZa6nhFpL1" role="gfFT$">
+          <ref role="37wK5l" to="ie8e:3OPtF03lcom" resolve="create" />
+          <ref role="1Pybhc" to="ie8e:3OPtF03lco4" resolve="ListBranch" />
+          <node concept="Xl_RD" id="6SZa6nhFpL2" role="37wK5m">
             <property role="Xl_RC" value="name" />
-            <node concept="17Uvod" id="1OShD0H$B7z" role="lGtFl">
+            <node concept="17Uvod" id="6SZa6nhFpL3" role="lGtFl">
               <property role="2qtEX9" value="value" />
               <property role="P4ACc" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1070475926800/1070475926801" />
-              <node concept="3zFVjK" id="1OShD0H$B7$" role="3zH0cK">
-                <node concept="3clFbS" id="1OShD0H$B7_" role="2VODD2">
-                  <node concept="3clFbF" id="1OShD0H$B7A" role="3cqZAp">
-                    <node concept="2OqwBi" id="1OShD0H$B7B" role="3clFbG">
-                      <node concept="30H73N" id="1OShD0H$B7C" role="2Oq$k0" />
-                      <node concept="3TrcHB" id="1OShD0H$B7D" role="2OqNvi">
+              <node concept="3zFVjK" id="6SZa6nhFpL4" role="3zH0cK">
+                <node concept="3clFbS" id="6SZa6nhFpL5" role="2VODD2">
+                  <node concept="3clFbF" id="6SZa6nhFpL6" role="3cqZAp">
+                    <node concept="2OqwBi" id="6SZa6nhFpL7" role="3clFbG">
+                      <node concept="30H73N" id="6SZa6nhFpL8" role="2Oq$k0" />
+                      <node concept="3TrcHB" id="6SZa6nhFpL9" role="2OqNvi">
                         <ref role="3TsBF5" to="tpck:h0TrG11" resolve="name" />
                       </node>
                     </node>
@@ -1629,16 +1715,16 @@
               </node>
             </node>
           </node>
-          <node concept="10Nm6u" id="1OShD0H$B7E" role="37wK5m">
-            <node concept="2b32R4" id="1OShD0H$B7F" role="lGtFl">
-              <node concept="3JmXsc" id="1OShD0H$B7G" role="2P8S$">
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-                  <node concept="3clFbF" id="1OShD0H$B7I" role="3cqZAp">
-                    <node concept="2OqwBi" id="1OShD0H$B7J" role="3clFbG">
-                      <node concept="3Tsc0h" id="1OShD0H$B7K" role="2OqNvi">
+          <node concept="10Nm6u" id="6SZa6nhFpLa" role="37wK5m">
+            <node concept="2b32R4" id="6SZa6nhFpLb" role="lGtFl">
+              <node concept="3JmXsc" id="6SZa6nhFpLc" role="2P8S$">
+                <node concept="3clFbS" id="6SZa6nhFpLd" role="2VODD2">
+                  <node concept="3clFbF" id="6SZa6nhFpLe" role="3cqZAp">
+                    <node concept="2OqwBi" id="6SZa6nhFpLf" role="3clFbG">
+                      <node concept="3Tsc0h" id="6SZa6nhFpLg" role="2OqNvi">
                         <ref role="3TtcxE" to="5j4j:6$jH9oLmYFB" />
                       </node>
-                      <node concept="30H73N" id="1OShD0H$B7L" role="2Oq$k0" />
+                      <node concept="30H73N" id="6SZa6nhFpLh" role="2Oq$k0" />
                     </node>
                   </node>
                 </node>
@@ -1888,79 +1974,79 @@
         </node>
       </node>
     </node>
-    <node concept="3aamgX" id="1OShD0H_hqp" role="3aUrZf">
+    <node concept="3aamgX" id="6SZa6nhEX$a" role="3aUrZf">
       <property role="36QftV" value="true" />
       <ref role="30HIoZ" to="5j4j:6$jH9oLmYC_" resolve="Node" />
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-        <node concept="2YIFZM" id="1OShD0H_iQ6" role="gfFT$">
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-          <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-          <node concept="Xl_RD" id="1OShD0H_iQ7" role="37wK5m">
+      <node concept="gft3U" id="6SZa6nhEX$b" role="1lVwrX">
+        <node concept="2YIFZM" id="6SZa6nhEZg2" role="gfFT$">
+          <ref role="37wK5l" to="ie8e:5JQSuNsxhfn" resolve="create" />
+          <ref role="1Pybhc" to="ie8e:5JQSuNswOXL" resolve="ChildrenBranch" />
+          <node concept="Xl_RD" id="6SZa6nhEZg3" role="37wK5m">
             <property role="Xl_RC" value="node" />
           </node>
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-                        <node concept="2OqwBi" id="1OShD0H_iQf" role="2Oq$k0">
-                          <node concept="3Tsc0h" id="1OShD0H_iQg" role="2OqNvi">
+          <node concept="10Nm6u" id="6SZa6nhEZg4" role="37wK5m">
+            <node concept="2b32R4" id="6SZa6nhEZg5" role="lGtFl">
+              <node concept="3JmXsc" id="6SZa6nhEZg6" role="2P8S$">
+                <node concept="3clFbS" id="6SZa6nhEZg7" role="2VODD2">
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+                      <node concept="2OqwBi" id="6SZa6nhEZga" role="2Oq$k0">
+                        <node concept="2OqwBi" id="6SZa6nhEZgb" role="2Oq$k0">
+                          <node concept="3Tsc0h" id="6SZa6nhEZgc" role="2OqNvi">
                             <ref role="3TtcxE" to="5j4j:6$jH9oLnyAp" />
                           </node>
-                          <node concept="30H73N" id="1OShD0H_iQh" role="2Oq$k0" />
+                          <node concept="30H73N" id="6SZa6nhEZgd" role="2Oq$k0" />
                         </node>
-                        <node concept="3zZkjj" id="1OShD0H_iQi" role="2OqNvi">
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-                                    <ref role="3cqZAo" node="1OShD0H_iQq" resolve="it" />
+                        <node concept="3zZkjj" id="6SZa6nhEZge" role="2OqNvi">
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+                                <node concept="2OqwBi" id="6SZa6nhEZgi" role="3clFbG">
+                                  <node concept="37vLTw" id="6SZa6nhEZgj" role="2Oq$k0">
+                                    <ref role="3cqZAo" node="6SZa6nhEZgm" resolve="it" />
                                   </node>
-                                  <node concept="1mIQ4w" id="1OShD0H_iQo" role="2OqNvi">
-                                    <node concept="chp4Y" id="1OShD0H_iQp" role="cj9EA">
+                                  <node concept="1mIQ4w" id="6SZa6nhEZgk" role="2OqNvi">
+                                    <node concept="chp4Y" id="6SZa6nhEZgl" role="cj9EA">
                                       <ref role="cht4Q" to="5j4j:6$jH9oLmYI0" resolve="ValueRole" />
                                     </node>
                                   </node>
                                 </node>
                               </node>
                             </node>
-                            <node concept="Rh6nW" id="1OShD0H_iQq" role="1bW2Oz">
+                            <node concept="Rh6nW" id="6SZa6nhEZgm" role="1bW2Oz">
                               <property role="TrG5h" value="it" />
-                              <node concept="2jxLKc" id="1OShD0H_iQr" role="1tU5fm" />
+                              <node concept="2jxLKc" id="6SZa6nhEZgn" role="1tU5fm" />
                             </node>
                           </node>
                         </node>
                       </node>
-                      <node concept="3QWeyG" id="1OShD0H_iQs" role="2OqNvi">
-                        <node concept="2OqwBi" id="1OShD0H_iQt" role="576Qk">
-                          <node concept="2OqwBi" id="1OShD0H_iQu" role="2Oq$k0">
-                            <node concept="30H73N" id="1OShD0H_iQv" role="2Oq$k0" />
-                            <node concept="3Tsc0h" id="1OShD0H_iQw" role="2OqNvi">
+                      <node concept="3QWeyG" id="6SZa6nhEZgo" role="2OqNvi">
+                        <node concept="2OqwBi" id="6SZa6nhEZgp" role="576Qk">
+                          <node concept="2OqwBi" id="6SZa6nhEZgq" role="2Oq$k0">
+                            <node concept="30H73N" id="6SZa6nhEZgr" role="2Oq$k0" />
+                            <node concept="3Tsc0h" id="6SZa6nhEZgs" role="2OqNvi">
                               <ref role="3TtcxE" to="5j4j:6$jH9oLnyAp" />
                             </node>
                           </node>
-                          <node concept="3zZkjj" id="1OShD0H_iQx" role="2OqNvi">
-                            <node concept="1bVj0M" id="1OShD0H_iQy" role="23t8la">
-                              <node concept="3clFbS" id="1OShD0H_iQz" role="1bW5cS">
-                                <node concept="3clFbF" id="1OShD0H_iQ$" role="3cqZAp">
-                                  <node concept="2OqwBi" id="1OShD0H_iQ_" role="3clFbG">
-                                    <node concept="37vLTw" id="1OShD0H_iQA" role="2Oq$k0">
-                                      <ref role="3cqZAo" node="1OShD0H_iQD" resolve="it" />
+                          <node concept="3zZkjj" id="6SZa6nhEZgt" role="2OqNvi">
+                            <node concept="1bVj0M" id="6SZa6nhEZgu" role="23t8la">
+                              <node concept="3clFbS" id="6SZa6nhEZgv" role="1bW5cS">
+                                <node concept="3clFbF" id="6SZa6nhEZgw" role="3cqZAp">
+                                  <node concept="2OqwBi" id="6SZa6nhEZgx" role="3clFbG">
+                                    <node concept="37vLTw" id="6SZa6nhEZgy" role="2Oq$k0">
+                                      <ref role="3cqZAo" node="6SZa6nhEZg_" resolve="it" />
                                     </node>
-                                    <node concept="1mIQ4w" id="1OShD0H_iQB" role="2OqNvi">
-                                      <node concept="chp4Y" id="1OShD0H_iQC" role="cj9EA">
+                                    <node concept="1mIQ4w" id="6SZa6nhEZgz" role="2OqNvi">
+                                      <node concept="chp4Y" id="6SZa6nhEZg$" role="cj9EA">
                                         <ref role="cht4Q" to="5j4j:6$jH9oLmYEJ" resolve="ChildRole" />
                                       </node>
                                     </node>
                                   </node>
                                 </node>
                               </node>
-                              <node concept="Rh6nW" id="1OShD0H_iQD" role="1bW2Oz">
+                              <node concept="Rh6nW" id="6SZa6nhEZg_" role="1bW2Oz">
                                 <property role="TrG5h" value="it" />
-                                <node concept="2jxLKc" id="1OShD0H_iQE" role="1tU5fm" />
+                                <node concept="2jxLKc" id="6SZa6nhEZgA" role="1tU5fm" />
                               </node>
                             </node>
                           </node>
diff --git a/languages/jetbrains.mps.logic/sandbox/models/jetbrains/mps/logic/sandbox.mps b/languages/jetbrains.mps.logic/sandbox/models/jetbrains/mps/logic/sandbox.mps
index 626143c8..416e00d6 100644
--- a/languages/jetbrains.mps.logic/sandbox/models/jetbrains/mps/logic/sandbox.mps
+++ b/languages/jetbrains.mps.logic/sandbox/models/jetbrains/mps/logic/sandbox.mps
@@ -63,9 +63,7 @@
         <child id="1070534934091" name="type" index="10QFUM" />
         <child id="1070534934092" name="expression" index="10QFUP" />
       </concept>
-      <concept id="1068390468198" name="jetbrains.mps.baseLanguage.structure.ClassConcept" flags="ig" index="312cEu">
-        <child id="1165602531693" name="superclass" index="1zkMxy" />
-      </concept>
+      <concept id="1068390468198" name="jetbrains.mps.baseLanguage.structure.ClassConcept" flags="ig" index="312cEu" />
       <concept id="1068431474542" name="jetbrains.mps.baseLanguage.structure.VariableDeclaration" flags="ng" index="33uBYm">
         <child id="1068431790190" name="initializer" index="33vP2m" />
       </concept>
@@ -184,460 +182,6 @@
       </concept>
     </language>
   </registry>
-  <node concept="312cEu" id="5JQSuNswWrq">
-    <property role="TrG5h" value="TreeBuilder" />
-    <node concept="2tJIrI" id="5JQSuNswWsu" role="jymVt" />
-    <node concept="2tJIrI" id="5JQSuNsx3tS" role="jymVt" />
-    <node concept="2YIFZL" id="5JQSuNs_q75" role="jymVt">
-      <property role="TrG5h" value="main" />
-      <property role="IEkAT" value="false" />
-      <property role="DiZV1" value="false" />
-      <property role="od$2w" value="false" />
-      <node concept="3clFbS" id="5JQSuNsx3JY" role="3clF47">
-        <node concept="3clFbH" id="5JQSuNsz8l9" role="3cqZAp" />
-        <node concept="3cpWs8" id="5JQSuNs_orP" role="3cqZAp">
-          <node concept="3cpWsn" id="5JQSuNs_orQ" role="3cpWs9">
-            <property role="TrG5h" value="tree" />
-            <node concept="3uibUv" id="5JQSuNs_orO" role="1tU5fm">
-              <ref role="3uigEE" to="ie8e:2xQ7eRABXh4" resolve="Tree" />
-            </node>
-            <node concept="2YIFZM" id="5JQSuNs_orR" role="33vP2m">
-              <ref role="37wK5l" to="ie8e:5JQSuNsxMa3" resolve="tree" />
-              <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-              <node concept="2YIFZM" id="5JQSuNs_orS" role="37wK5m">
-                <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-                <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                <node concept="Xl_RD" id="5JQSuNs_orT" role="37wK5m">
-                  <property role="Xl_RC" value="node1" />
-                </node>
-                <node concept="2YIFZM" id="5JQSuNs_orU" role="37wK5m">
-                  <ref role="37wK5l" to="ie8e:5JQSuNsx4I5" resolve="value" />
-                  <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                  <node concept="Xl_RD" id="5JQSuNs_orV" role="37wK5m">
-                    <property role="Xl_RC" value="prop1" />
-                  </node>
-                  <node concept="Xl_RD" id="5JQSuNs_orW" role="37wK5m">
-                    <property role="Xl_RC" value="value" />
-                  </node>
-                </node>
-                <node concept="2YIFZM" id="5JQSuNs_orX" role="37wK5m">
-                  <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-                  <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                  <node concept="Xl_RD" id="5JQSuNs_orY" role="37wK5m">
-                    <property role="Xl_RC" value="child1" />
-                  </node>
-                  <node concept="2YIFZM" id="5JQSuNs_orZ" role="37wK5m">
-                    <ref role="37wK5l" to="ie8e:5JQSuNsxgzn" resolve="child" />
-                    <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-                    <node concept="Xl_RD" id="5JQSuNs_os0" role="37wK5m">
-                      <property role="Xl_RC" value="node2" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbH" id="5JQSuNs_pxu" role="3cqZAp" />
-        <node concept="3clFbF" id="5JQSuNs_sUc" role="3cqZAp">
-          <node concept="2OqwBi" id="5JQSuNs_sU8" role="3clFbG">
-            <node concept="10M0yZ" id="5JQSuNs_sU9" role="2Oq$k0">
-              <ref role="1PxDUh" to="e2lb:~System" resolve="System" />
-              <ref role="3cqZAo" to="e2lb:~System.out" resolve="out" />
-            </node>
-            <node concept="liA8E" id="5JQSuNs_sUa" role="2OqNvi">
-              <ref role="37wK5l" to="fxg7:~PrintStream.println(java.lang.String):void" resolve="println" />
-              <node concept="3cpWs3" id="5JQSuNs_tQP" role="37wK5m">
-                <node concept="Xl_RD" id="5JQSuNs_sUb" role="3uHU7B">
-                  <property role="Xl_RC" value="&gt; " />
-                </node>
-                <node concept="2OqwBi" id="5JQSuNs_tA3" role="3uHU7w">
-                  <node concept="37vLTw" id="5JQSuNs_tA4" role="2Oq$k0">
-                    <ref role="3cqZAo" node="5JQSuNs_orQ" resolve="tree" />
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-                  <node concept="liA8E" id="5JQSuNs_tA5" role="2OqNvi">
-                    <ref role="37wK5l" to="ie8e:5JQSuNs_vzS" resolve="toString" />
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-                </node>
-              </node>
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-          </node>
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-        <node concept="3clFbH" id="uNmovXfqew" role="3cqZAp" />
-        <node concept="3cpWs8" id="uNmovXg2L7" role="3cqZAp">
-          <node concept="3cpWsn" id="uNmovXg2L8" role="3cpWs9">
-            <property role="TrG5h" value="tree2" />
-            <node concept="3uibUv" id="uNmovXg2KU" role="1tU5fm">
-              <ref role="3uigEE" to="ie8e:2xQ7eRABXh4" resolve="Tree" />
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-              <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
-              <ref role="37wK5l" to="ie8e:5JQSuNsxMa3" resolve="tree" />
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-                <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
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-                  <property role="Xl_RC" value="node1" />
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-                <node concept="2YIFZM" id="uNmovXg2Lc" role="37wK5m">
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-                  <node concept="Xl_RD" id="uNmovXg2Le" role="37wK5m">
-                    <property role="Xl_RC" value="ClassifierType" />
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-                <node concept="2YIFZM" id="uNmovXg2Lf" role="37wK5m">
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-                  <node concept="Xl_RD" id="uNmovXg2Lg" role="37wK5m">
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-                  <node concept="Xl_RD" id="uNmovXg2Lh" role="37wK5m">
-                    <property role="Xl_RC" value="List" />
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-                </node>
-                <node concept="2YIFZM" id="uNmovXg2Li" role="37wK5m">
-                  <ref role="1Pybhc" to="ie8e:5JQSuNsx4Gq" resolve="Builder" />
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-                  <node concept="Xl_RD" id="uNmovXg2Lj" role="37wK5m">
-                    <property role="Xl_RC" value="parameter" />
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-                  <node concept="2YIFZM" id="uNmovXg2Lk" role="37wK5m">
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-                      <property role="Xl_RC" value="node2" />
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-                    <node concept="2YIFZM" id="uNmovXg2Lm" role="37wK5m">
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-                      <node concept="Xl_RD" id="uNmovXg2Lo" role="37wK5m">
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-                    <node concept="2YIFZM" id="uNmovXg2Lp" role="37wK5m">
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-                      <node concept="Xl_RD" id="uNmovXg2Lq" role="37wK5m">
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-                      <node concept="Xl_RD" id="uNmovXg2Lr" role="37wK5m">
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-        <node concept="3clFbH" id="uNmovXg8NB" role="3cqZAp" />
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-            <node concept="liA8E" id="uNmovXgaj6" role="2OqNvi">
-              <ref role="37wK5l" to="fxg7:~PrintStream.println(java.lang.String):void" resolve="println" />
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-                <node concept="Xl_RD" id="uNmovXgaj7" role="3uHU7B">
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-        <node concept="3clFbH" id="5JQSuNsxPhi" role="3cqZAp" />
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-    </node>
-  </node>
   <node concept="312cEu" id="1pt0VTMCtZb">
     <property role="TrG5h" value="DslTest" />
     <node concept="2tJIrI" id="1pt0VTMCtZx" role="jymVt" />
diff --git a/solutions/jetbrains.mps.typechecking.handling/models/jetbrains/mps/typechecking/handler/producer.mps b/solutions/jetbrains.mps.typechecking.handling/models/jetbrains/mps/typechecking/handler/producer.mps
index d3ebab6c..b6e5ae4e 100644
--- a/solutions/jetbrains.mps.typechecking.handling/models/jetbrains/mps/typechecking/handler/producer.mps
+++ b/solutions/jetbrains.mps.typechecking.handling/models/jetbrains/mps/typechecking/handler/producer.mps
@@ -4550,7 +4550,7 @@
                         <node concept="liA8E" id="677NV56yw_Z" role="2OqNvi">
                           <ref role="37wK5l" to="e2lb:~String.startsWith(java.lang.String):boolean" resolve="startsWith" />
                           <node concept="Xl_RD" id="677NV56ywEl" role="37wK5m">
-                            <property role="Xl_RC" value="$" />
+                            <property role="Xl_RC" value="_" />
                           </node>
                         </node>
                       </node>
@@ -4755,7 +4755,7 @@
                   <node concept="liA8E" id="677NV56dlaq" role="2OqNvi">
                     <ref role="37wK5l" to="e2lb:~String.startsWith(java.lang.String):boolean" resolve="startsWith" />
                     <node concept="Xl_RD" id="677NV56dlcE" role="37wK5m">
-                      <property role="Xl_RC" value="$" />
+                      <property role="Xl_RC" value="_" />
                     </node>
                   </node>
                   <node concept="2YIFZM" id="31Jz$8bZWnC" role="2Oq$k0">
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 a1b14144..b2f6e048 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
@@ -2873,313 +2873,18 @@
   </node>
   <node concept="312cEu" id="5JQSuNsx4Gq">
     <property role="TrG5h" value="Builder" />
-    <node concept="2tJIrI" id="5s497VqlBzx" role="jymVt" />
-    <node concept="2YIFZL" id="5JQSuNsxMa3" role="jymVt">
-      <property role="TrG5h" value="tree" />
-      <property role="od$2w" value="false" />
-      <property role="DiZV1" value="false" />
-      <node concept="37vLTG" id="5JQSuNsxMbQ" role="3clF46">
-        <property role="TrG5h" value="root" />
-        <node concept="3uibUv" id="1bm7a6FhUlX" role="1tU5fm">
-          <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
-          <node concept="3qUE_q" id="1bm7a6FkkYL" role="11_B2D">
-            <node concept="3uibUv" id="1bm7a6Fkl64" role="3qUE_r">
-              <ref role="3uigEE" to="jfki:~Node" resolve="Node" />
-            </node>
-          </node>
+    <property role="IEkAT" value="false" />
+    <node concept="2AHcQZ" id="6SZa6nhFycG" role="2AJF6D">
+      <ref role="2AI5Lk" to="e2lb:~Deprecated" resolve="Deprecated" />
+    </node>
+    <node concept="3UR2Jj" id="6SZa6nhFyaX" role="lGtFl">
+      <node concept="TZ5HA" id="6SZa6nhFyaY" role="TZ5H$">
+        <node concept="1dT_AC" id="6SZa6nhFyaZ" role="1dT_Ay">
+          <property role="1dT_AB" value="TODO: to be merged with ValuesBranch" />
         </node>
       </node>
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-      <property role="TrG5h" value="child" />
-      <property role="od$2w" value="false" />
-      <property role="DiZV1" value="false" />
-      <node concept="37vLTG" id="5JQSuNsxg_M" role="3clF46">
-        <property role="TrG5h" value="symbol" />
-        <node concept="3uibUv" id="6$jH9oLaltF" role="1tU5fm">
-          <ref role="3uigEE" to="e2lb:~Object" resolve="Object" />
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-      <node concept="37vLTG" id="5JQSuNsxgAm" role="3clF46">
-        <property role="TrG5h" value="children" />
-        <node concept="8X2XB" id="5JQSuNsxjiz" role="1tU5fm">
-          <node concept="3uibUv" id="5JQSuNsxjhT" role="8Xvag">
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-          <node concept="3SKdUq" id="7jC45KcbPi6" role="3SKWNk">
-            <property role="3SKdUp" value="TODO hacking the builder" />
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-                </node>
-                <node concept="16syzq" id="1OShD0HZW7f" role="3PaCim">
-                  <ref role="16sUi3" node="5JQSuNsxhVi" resolve="T" />
-                </node>
-              </node>
-            </node>
-          </node>
-          <node concept="1Wc70l" id="1OShD0HZKbm" role="3clFbw">
-            <node concept="2ZW3vV" id="1OShD0HZKD7" role="3uHU7w">
-              <node concept="3uibUv" id="1OShD0HZKT_" role="2ZW6by">
-                <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
-              </node>
-              <node concept="AH0OO" id="1OShD0HZKth" role="2ZW6bz">
-                <node concept="3cmrfG" id="1OShD0HZKyM" role="AHEQo">
-                  <property role="3cmrfH" value="0" />
-                </node>
-                <node concept="37vLTw" id="1OShD0HZKnM" role="AHHXb">
-                  <ref role="3cqZAo" node="5JQSuNsxgAm" resolve="children" />
-                </node>
-              </node>
-            </node>
-            <node concept="3clFbC" id="1OShD0HZJOG" role="3uHU7B">
-              <node concept="2OqwBi" id="1OShD0HZIxV" role="3uHU7B">
-                <node concept="37vLTw" id="1OShD0HZIoQ" role="2Oq$k0">
-                  <ref role="3cqZAo" node="5JQSuNsxgAm" resolve="children" />
-                </node>
-                <node concept="1Rwk04" id="1OShD0HZJbJ" role="2OqNvi" />
-              </node>
-              <node concept="3cmrfG" id="1OShD0HZJPd" role="3uHU7w">
-                <property role="3cmrfH" value="1" />
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbF" id="5JQSuNsxjjJ" role="3cqZAp">
-          <node concept="10QFUN" id="1OShD0HYitc" role="3clFbG">
-            <node concept="2YIFZM" id="1OShD0HYit8" role="10QFUP">
-              <ref role="37wK5l" node="5JQSuNsxhfn" resolve="create" />
-              <ref role="1Pybhc" node="5JQSuNswOXL" resolve="ChildrenBranch" />
-              <node concept="37vLTw" id="1OShD0HYit9" role="37wK5m">
-                <ref role="3cqZAo" node="5JQSuNsxg_M" resolve="symbol" />
-              </node>
-              <node concept="37vLTw" id="1OShD0HYita" role="37wK5m">
-                <ref role="3cqZAo" node="5JQSuNsxgAm" resolve="children" />
-              </node>
-              <node concept="16syzq" id="1OShD0HYitb" role="3PaCim">
-                <ref role="16sUi3" node="5JQSuNsxhVi" resolve="T" />
-              </node>
-            </node>
-            <node concept="3uibUv" id="1OShD0HYiFL" role="10QFUM">
-              <ref role="3uigEE" node="1msb0mq9ID4" resolve="Branch" />
-              <node concept="16syzq" id="1OShD0HYiFM" role="11_B2D">
-                <ref role="16sUi3" node="5JQSuNsxhVi" resolve="T" />
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="3Tm1VV" id="5JQSuNsxgwP" role="1B3o_S" />
-      <node concept="3uibUv" id="5JQSuNsxgzf" role="3clF45">
-        <ref role="3uigEE" node="1msb0mq9ID4" resolve="Branch" />
-        <node concept="16syzq" id="uNmovXd901" role="11_B2D">
-          <ref role="16sUi3" node="5JQSuNsxhVi" resolve="T" />
-        </node>
-      </node>
-      <node concept="16euLQ" id="5JQSuNsxhVi" role="16eVyc">
-        <property role="TrG5h" value="T" />
-        <node concept="3uibUv" id="3OPtF03eqU7" role="3ztrMU">
-          <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
-          <node concept="3qTvmN" id="3OPtF03eqZY" role="11_B2D" />
-        </node>
-      </node>
-    </node>
-    <node concept="2tJIrI" id="1OShD0HVS6u" role="jymVt" />
-    <node concept="2YIFZL" id="1OShD0HVRI3" role="jymVt">
-      <property role="TrG5h" value="child" />
-      <property role="od$2w" value="false" />
-      <property role="DiZV1" value="false" />
-      <node concept="37vLTG" id="1OShD0HVRI4" role="3clF46">
-        <property role="TrG5h" value="symbol" />
-        <node concept="3uibUv" id="1OShD0HVRI5" role="1tU5fm">
-          <ref role="3uigEE" to="e2lb:~Object" resolve="Object" />
-        </node>
-      </node>
-      <node concept="37vLTG" id="1OShD0HVRI6" role="3clF46">
-        <property role="TrG5h" value="list" />
-        <node concept="3uibUv" id="1OShD0HVTe8" role="1tU5fm">
-          <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
-          <node concept="16syzq" id="1OShD0HW2lq" role="11_B2D">
-            <ref role="16sUi3" node="1OShD0HVRIj" resolve="T" />
-          </node>
-        </node>
-      </node>
-      <node concept="3clFbS" id="1OShD0HVRIa" role="3clF47">
-        <node concept="3SKdUt" id="1OShD0HW6Qw" role="3cqZAp">
-          <node concept="3SKdUq" id="1OShD0HW70Q" role="3SKWNk">
-            <property role="3SKdUp" value="TODO: avoid unnecessary cast" />
-          </node>
-        </node>
-        <node concept="3clFbF" id="1OShD0HVWup" role="3cqZAp">
-          <node concept="10QFUN" id="1OShD0HW63Z" role="3clFbG">
-            <node concept="2YIFZM" id="1OShD0HW63W" role="10QFUP">
-              <ref role="1Pybhc" node="3OPtF03lco4" resolve="ListBranch" />
-              <ref role="37wK5l" node="1OShD0HL7j9" resolve="create" />
-              <node concept="37vLTw" id="1OShD0HW63X" role="37wK5m">
-                <ref role="3cqZAo" node="1OShD0HVRI4" resolve="symbol" />
-              </node>
-              <node concept="37vLTw" id="1OShD0HW63Y" role="37wK5m">
-                <ref role="3cqZAo" node="1OShD0HVRI6" resolve="list" />
-              </node>
-            </node>
-            <node concept="3uibUv" id="1OShD0HW6gd" role="10QFUM">
-              <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
-              <node concept="16syzq" id="1OShD0HW6zU" role="11_B2D">
-                <ref role="16sUi3" node="1OShD0HVRIj" resolve="T" />
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="3Tm1VV" id="1OShD0HVRIg" role="1B3o_S" />
-      <node concept="3uibUv" id="1OShD0HVRIh" role="3clF45">
-        <ref role="3uigEE" node="1msb0mq9ID4" resolve="Branch" />
-        <node concept="16syzq" id="1OShD0HVRIi" role="11_B2D">
-          <ref role="16sUi3" node="1OShD0HVRIj" resolve="T" />
-        </node>
-      </node>
-      <node concept="16euLQ" id="1OShD0HVRIj" role="16eVyc">
-        <property role="TrG5h" value="T" />
-        <node concept="3uibUv" id="1OShD0HVRIk" role="3ztrMU">
-          <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
-          <node concept="3qTvmN" id="1OShD0HVRIl" role="11_B2D" />
-        </node>
-      </node>
-    </node>
-    <node concept="2tJIrI" id="1R$Cm9qHyZy" role="jymVt" />
-    <node concept="2YIFZL" id="6$jH9oLaYQA" role="jymVt">
-      <property role="TrG5h" value="childrenList" />
-      <property role="od$2w" value="false" />
-      <property role="DiZV1" value="false" />
-      <node concept="37vLTG" id="6$jH9oLhhp2" role="3clF46">
-        <property role="TrG5h" value="symbol" />
-        <node concept="3uibUv" id="6$jH9oLhhVz" role="1tU5fm">
-          <ref role="3uigEE" to="e2lb:~Object" resolve="Object" />
-        </node>
-      </node>
-      <node concept="37vLTG" id="6$jH9oLaYQB" role="3clF46">
-        <property role="TrG5h" value="children" />
-        <node concept="8X2XB" id="6$jH9oLaYQC" role="1tU5fm">
-          <node concept="3uibUv" id="1bm7a6F18Nx" role="8Xvag">
-            <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
-            <node concept="3qTvmN" id="dfChU1l2u0" role="11_B2D" />
-          </node>
-        </node>
-      </node>
-      <node concept="3clFbS" id="6$jH9oLaYQF" role="3clF47">
-        <node concept="3SKdUt" id="1OShD0I73EH" role="3cqZAp">
-          <node concept="3SKdUq" id="1OShD0I73EI" role="3SKWNk">
-            <property role="3SKdUp" value="TODO: avoid unnecessary cast" />
-          </node>
-        </node>
-        <node concept="3clFbF" id="6$jH9oLfPDC" role="3cqZAp">
-          <node concept="10QFUN" id="1OShD0I713R" role="3clFbG">
-            <node concept="2YIFZM" id="1OShD0I713N" role="10QFUP">
-              <ref role="1Pybhc" node="3OPtF03lco4" resolve="ListBranch" />
-              <ref role="37wK5l" node="3OPtF03lcom" resolve="create" />
-              <node concept="37vLTw" id="1OShD0I713O" role="37wK5m">
-                <ref role="3cqZAo" node="6$jH9oLhhp2" resolve="symbol" />
-              </node>
-              <node concept="37vLTw" id="1OShD0I713P" role="37wK5m">
-                <ref role="3cqZAo" node="6$jH9oLaYQB" resolve="children" />
-              </node>
-            </node>
-            <node concept="3uibUv" id="1OShD0I71VN" role="10QFUM">
-              <ref role="3uigEE" node="1msb0mq9ID4" resolve="Branch" />
-              <node concept="16syzq" id="1OShD0I71VO" role="11_B2D">
-                <ref role="16sUi3" node="6$jH9oLaYQO" resolve="T" />
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="3Tm1VV" id="6$jH9oLaYQL" role="1B3o_S" />
-      <node concept="3uibUv" id="6$jH9oLaYQM" role="3clF45">
-        <ref role="3uigEE" node="1msb0mq9ID4" resolve="Branch" />
-        <node concept="16syzq" id="6$jH9oLkczs" role="11_B2D">
-          <ref role="16sUi3" node="6$jH9oLaYQO" resolve="T" />
-        </node>
-      </node>
-      <node concept="16euLQ" id="6$jH9oLaYQO" role="16eVyc">
-        <property role="TrG5h" value="T" />
-        <node concept="3uibUv" id="1bm7a6F15XH" role="3ztrMU">
-          <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
-          <node concept="3qTvmN" id="2q_78a93Y_I" role="11_B2D" />
-        </node>
-      </node>
-    </node>
-    <node concept="2tJIrI" id="53iOybEJRMZ" role="jymVt" />
     <node concept="2YIFZL" id="5JQSuNsx4I5" role="jymVt">
       <property role="TrG5h" value="value" />
       <property role="od$2w" value="false" />
@@ -9591,6 +9296,63 @@
       </node>
     </node>
     <node concept="2tJIrI" id="1OShD0HLb9_" role="jymVt" />
+    <node concept="2YIFZL" id="1OShD0HS45f" role="jymVt">
+      <property role="TrG5h" value="createList" />
+      <node concept="37vLTG" id="1OShD0HSc64" role="3clF46">
+        <property role="TrG5h" value="elements" />
+        <node concept="8X2XB" id="1OShD0HSHQT" role="1tU5fm">
+          <node concept="3uibUv" id="1OShD0HSc66" role="8Xvag">
+            <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
+            <node concept="3qTvmN" id="1OShD0I1cw7" role="11_B2D" />
+          </node>
+        </node>
+      </node>
+      <node concept="3uibUv" id="1OShD0HS7CO" role="3clF45">
+        <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
+        <node concept="16syzq" id="1OShD0HSE4C" role="11_B2D">
+          <ref role="16sUi3" node="1OShD0HSa_P" resolve="T" />
+        </node>
+      </node>
+      <node concept="3Tm1VV" id="1OShD0HS45i" role="1B3o_S" />
+      <node concept="3clFbS" id="1OShD0HS45j" role="3clF47">
+        <node concept="3SKdUt" id="1OShD0HT1H6" role="3cqZAp">
+          <node concept="3SKdUq" id="1OShD0HT1H7" role="3SKWNk">
+            <property role="3SKdUp" value="TODO: avoid unnecessary cast" />
+          </node>
+        </node>
+        <node concept="3clFbF" id="1OShD0HSd7a" role="3cqZAp">
+          <node concept="10QFUN" id="1OShD0HSXZ6" role="3clFbG">
+            <node concept="1rXfSq" id="1OShD0HSXZ3" role="10QFUP">
+              <ref role="37wK5l" node="3OPtF03lcoL" resolve="createList" />
+              <node concept="37vLTw" id="1OShD0HSXZ4" role="37wK5m">
+                <ref role="3cqZAo" node="1OShD0HSc64" resolve="elements" />
+              </node>
+              <node concept="3cmrfG" id="1OShD0HSXZ5" role="37wK5m">
+                <property role="3cmrfH" value="0" />
+              </node>
+            </node>
+            <node concept="3uibUv" id="1OShD0HSYLa" role="10QFUM">
+              <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
+              <node concept="16syzq" id="1OShD0HSYLb" role="11_B2D">
+                <ref role="16sUi3" node="1OShD0HSa_P" resolve="T" />
+              </node>
+            </node>
+          </node>
+        </node>
+      </node>
+      <node concept="16euLQ" id="1OShD0HSa_P" role="16eVyc">
+        <property role="TrG5h" value="T" />
+        <node concept="3uibUv" id="1OShD0HSa_Q" role="3ztrMU">
+          <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
+          <node concept="3qUE_q" id="1OShD0HSa_R" role="11_B2D">
+            <node concept="3uibUv" id="1OShD0HSa_S" role="3qUE_r">
+              <ref role="3uigEE" to="jfki:~Node" resolve="Node" />
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
+    <node concept="2tJIrI" id="3OPtF03lcoK" role="jymVt" />
     <node concept="2YIFZL" id="1OShD0HL7j9" role="jymVt">
       <property role="TrG5h" value="create" />
       <property role="od$2w" value="false" />
@@ -9849,63 +9611,6 @@
       </node>
     </node>
     <node concept="2tJIrI" id="1OShD0HRYaK" role="jymVt" />
-    <node concept="2YIFZL" id="1OShD0HS45f" role="jymVt">
-      <property role="TrG5h" value="createList" />
-      <node concept="37vLTG" id="1OShD0HSc64" role="3clF46">
-        <property role="TrG5h" value="elements" />
-        <node concept="8X2XB" id="1OShD0HSHQT" role="1tU5fm">
-          <node concept="3uibUv" id="1OShD0HSc66" role="8Xvag">
-            <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
-            <node concept="3qTvmN" id="1OShD0I1cw7" role="11_B2D" />
-          </node>
-        </node>
-      </node>
-      <node concept="3uibUv" id="1OShD0HS7CO" role="3clF45">
-        <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
-        <node concept="16syzq" id="1OShD0HSE4C" role="11_B2D">
-          <ref role="16sUi3" node="1OShD0HSa_P" resolve="T" />
-        </node>
-      </node>
-      <node concept="3Tm1VV" id="1OShD0HS45i" role="1B3o_S" />
-      <node concept="3clFbS" id="1OShD0HS45j" role="3clF47">
-        <node concept="3SKdUt" id="1OShD0HT1H6" role="3cqZAp">
-          <node concept="3SKdUq" id="1OShD0HT1H7" role="3SKWNk">
-            <property role="3SKdUp" value="TODO: avoid unnecessary cast" />
-          </node>
-        </node>
-        <node concept="3clFbF" id="1OShD0HSd7a" role="3cqZAp">
-          <node concept="10QFUN" id="1OShD0HSXZ6" role="3clFbG">
-            <node concept="1rXfSq" id="1OShD0HSXZ3" role="10QFUP">
-              <ref role="37wK5l" node="3OPtF03lcoL" resolve="createList" />
-              <node concept="37vLTw" id="1OShD0HSXZ4" role="37wK5m">
-                <ref role="3cqZAo" node="1OShD0HSc64" resolve="elements" />
-              </node>
-              <node concept="3cmrfG" id="1OShD0HSXZ5" role="37wK5m">
-                <property role="3cmrfH" value="0" />
-              </node>
-            </node>
-            <node concept="3uibUv" id="1OShD0HSYLa" role="10QFUM">
-              <ref role="3uigEE" node="3OPtF03lco4" resolve="ListBranch" />
-              <node concept="16syzq" id="1OShD0HSYLb" role="11_B2D">
-                <ref role="16sUi3" node="1OShD0HSa_P" resolve="T" />
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="16euLQ" id="1OShD0HSa_P" role="16eVyc">
-        <property role="TrG5h" value="T" />
-        <node concept="3uibUv" id="1OShD0HSa_Q" role="3ztrMU">
-          <ref role="3uigEE" node="1bm7a6EXvsP" resolve="ITreePart" />
-          <node concept="3qUE_q" id="1OShD0HSa_R" role="11_B2D">
-            <node concept="3uibUv" id="1OShD0HSa_S" role="3qUE_r">
-              <ref role="3uigEE" to="jfki:~Node" resolve="Node" />
-            </node>
-          </node>
-        </node>
-      </node>
-    </node>
-    <node concept="2tJIrI" id="3OPtF03lcoK" role="jymVt" />
     <node concept="2YIFZL" id="3OPtF03lcoL" role="jymVt">
       <property role="TrG5h" value="createList" />
       <property role="od$2w" value="false" />
@@ -10042,7 +9747,50 @@
                   </node>
                 </node>
               </node>
+              <node concept="3clFbH" id="6SZa6nhOdO_" role="3cqZAp" />
+              <node concept="3SKdUt" id="6SZa6nhOb5k" role="3cqZAp">
+                <node concept="3SKdUq" id="6SZa6nhObsj" role="3SKWNk">
+                  <property role="3SKdUp" value="FIXME: hack, support &quot;list variables&quot; instead" />
+                </node>
+              </node>
               <node concept="3clFbJ" id="1OShD0IbW7W" role="3cqZAp">
+                <node concept="1Wc70l" id="6SZa6nhO4TG" role="3clFbw">
+                  <node concept="2ZW3vV" id="1OShD0IbXxR" role="3uHU7B">
+                    <node concept="3uibUv" id="1OShD0IbXTQ" role="2ZW6by">
+                      <ref role="3uigEE" node="uNmovXiEd4" resolve="Variable" />
+                    </node>
+                    <node concept="37vLTw" id="1OShD0IbXfa" role="2ZW6bz">
+                      <ref role="3cqZAo" node="1OShD0IbQqE" resolve="last" />
+                    </node>
+                  </node>
+                  <node concept="2OqwBi" id="6SZa6nhO7VC" role="3uHU7w">
+                    <node concept="2YIFZM" id="6SZa6nhO756" role="2Oq$k0">
+                      <ref role="37wK5l" to="e2lb:~String.valueOf(java.lang.Object):java.lang.String" resolve="valueOf" />
+                      <ref role="1Pybhc" to="e2lb:~String" resolve="String" />
+                      <node concept="2OqwBi" id="6SZa6nhO6le" role="37wK5m">
+                        <node concept="1eOMI4" id="6SZa6nhO5SQ" role="2Oq$k0">
+                          <node concept="10QFUN" id="6SZa6nhO5SN" role="1eOMHV">
+                            <node concept="3uibUv" id="6SZa6nhO5YM" role="10QFUM">
+                              <ref role="3uigEE" node="uNmovXiEd4" resolve="Variable" />
+                            </node>
+                            <node concept="37vLTw" id="6SZa6nhO69n" role="10QFUP">
+                              <ref role="3cqZAo" node="1OShD0IbQqE" resolve="last" />
+                            </node>
+                          </node>
+                        </node>
+                        <node concept="liA8E" id="6SZa6nhO6M9" role="2OqNvi">
+                          <ref role="37wK5l" node="56MMu0Ark7d" resolve="symbol" />
+                        </node>
+                      </node>
+                    </node>
+                    <node concept="liA8E" id="6SZa6nhO8tl" role="2OqNvi">
+                      <ref role="37wK5l" to="e2lb:~String.startsWith(java.lang.String):boolean" resolve="startsWith" />
+                      <node concept="Xl_RD" id="6SZa6nhO8zJ" role="37wK5m">
+                        <property role="Xl_RC" value="_" />
+                      </node>
+                    </node>
+                  </node>
+                </node>
                 <node concept="3clFbS" id="1OShD0IbW7Y" role="3clFbx">
                   <node concept="3cpWs6" id="1OShD0IchsR" role="3cqZAp">
                     <node concept="10QFUN" id="1OShD0Iehgy" role="3cqZAk">
@@ -10067,14 +9815,6 @@
                   </node>
                   <node concept="3clFbH" id="1OShD0Ic6Ap" role="3cqZAp" />
                 </node>
-                <node concept="2ZW3vV" id="1OShD0IbXxR" role="3clFbw">
-                  <node concept="3uibUv" id="1OShD0IbXTQ" role="2ZW6by">
-                    <ref role="3uigEE" node="uNmovXiEd4" resolve="Variable" />
-                  </node>
-                  <node concept="37vLTw" id="1OShD0IbXfa" role="2ZW6bz">
-                    <ref role="3cqZAo" node="1OShD0IbQqE" resolve="last" />
-                  </node>
-                </node>
                 <node concept="9aQIb" id="1OShD0Ic2Cw" role="9aQIa">
                   <node concept="3clFbS" id="1OShD0Ic2Cx" role="9aQI4">
                     <node concept="3cpWs8" id="1OShD0IbQqJ" role="3cqZAp">