diff --git a/samples/mpscore/solutions/typechecking.samples.baseLanguage/models/typechecking.samples.baseLanguage.incrementalBL@tests.mps b/samples/mpscore/solutions/typechecking.samples.baseLanguage/models/typechecking.samples.baseLanguage.incrementalBL@tests.mps
index 6e57c46a..a453c3c1 100644
--- a/samples/mpscore/solutions/typechecking.samples.baseLanguage/models/typechecking.samples.baseLanguage.incrementalBL@tests.mps
+++ b/samples/mpscore/solutions/typechecking.samples.baseLanguage/models/typechecking.samples.baseLanguage.incrementalBL@tests.mps
@@ -25,6 +25,7 @@
     <import index="zx3l" ref="bbf5c548-7111-4a53-a117-cdefc664cf34/java:jetbrains.mps.logic.reactor.core(jetbrains.mps.logic.reactor/)" />
     <import index="w7la" ref="bbf5c548-7111-4a53-a117-cdefc664cf34/java:jetbrains.mps.logic.reactor.evaluation(jetbrains.mps.logic.reactor/)" />
     <import index="26pr" ref="r:6924fbc1-8fd5-471c-92d4-4cc382db0461(jetbrains.mps.baseLanguageExt.structure)" />
+    <import index="tpd4" ref="r:00000000-0000-4000-0000-011c895902b4(jetbrains.mps.lang.typesystem.structure)" />
     <import index="wyt6" ref="6354ebe7-c22a-4a0f-ac54-50b52ab9b065/java:java.lang(JDK/)" implicit="true" />
     <import index="33ny" ref="6354ebe7-c22a-4a0f-ac54-50b52ab9b065/java:java.util(JDK/)" implicit="true" />
     <import index="tpcu" ref="r:00000000-0000-4000-0000-011c89590282(jetbrains.mps.lang.core.behavior)" implicit="true" />
@@ -50,6 +51,7 @@
       <concept id="1225978065297" name="jetbrains.mps.lang.test.structure.SimpleNodeTest" flags="ng" index="1LZb2c" />
     </language>
     <language id="f3061a53-9226-4cc5-a443-f952ceaf5816" name="jetbrains.mps.baseLanguage">
+      <concept id="1080223426719" name="jetbrains.mps.baseLanguage.structure.OrExpression" flags="nn" index="22lmx$" />
       <concept id="1082485599095" name="jetbrains.mps.baseLanguage.structure.BlockStatement" flags="nn" index="9aQIb">
         <child id="1082485599096" name="statements" index="9aQI4" />
       </concept>
@@ -218,12 +220,19 @@
       </concept>
     </language>
     <language id="7866978e-a0f0-4cc7-81bc-4d213d9375e1" name="jetbrains.mps.lang.smodel">
+      <concept id="1177026924588" name="jetbrains.mps.lang.smodel.structure.RefConcept_Reference" flags="nn" index="chp4Y">
+        <reference id="1177026940964" name="conceptDeclaration" index="cht4Q" />
+      </concept>
       <concept id="1179409122411" name="jetbrains.mps.lang.smodel.structure.Node_ConceptMethodCall" flags="nn" index="2qgKlT" />
       <concept id="1145404486709" name="jetbrains.mps.lang.smodel.structure.SemanticDowncastExpression" flags="nn" index="2JrnkZ">
         <child id="1145404616321" name="leftExpression" index="2JrQYb" />
       </concept>
       <concept id="1227264722563" name="jetbrains.mps.lang.smodel.structure.EqualsStructurallyExpression" flags="nn" index="2YFouu" />
       <concept id="1139613262185" name="jetbrains.mps.lang.smodel.structure.Node_GetParentOperation" flags="nn" index="1mfA1w" />
+      <concept id="1139621453865" name="jetbrains.mps.lang.smodel.structure.Node_IsInstanceOfOperation" flags="nn" index="1mIQ4w">
+        <child id="1177027386292" name="conceptArgument" index="cj9EA" />
+      </concept>
+      <concept id="1171999116870" name="jetbrains.mps.lang.smodel.structure.Node_IsNullOperation" flags="nn" index="3w_OXm" />
       <concept id="1144146199828" name="jetbrains.mps.lang.smodel.structure.Node_CopyOperation" flags="nn" index="1$rogu" />
       <concept id="1140131837776" name="jetbrains.mps.lang.smodel.structure.Node_ReplaceWithAnotherOperation" flags="nn" index="1P9Npp">
         <child id="1140131861877" name="replacementNode" index="1P9ThW" />
@@ -749,50 +758,44 @@
         <node concept="3clFbH" id="4t5t2tf9LFD" role="3cqZAp" />
         <node concept="3clFbJ" id="4t5t2tf9LFV" role="3cqZAp">
           <node concept="3clFbS" id="4t5t2tf9LFW" role="3clFbx">
-            <node concept="3SKdUt" id="2JTW8QYmJTb" role="3cqZAp">
-              <node concept="1PaTwC" id="2JTW8QYmJTc" role="3ndbpf">
-                <node concept="3oM_SD" id="2JTW8QYmJTe" role="1PaTwD">
-                  <property role="3oM_SC" value="it's" />
-                </node>
-                <node concept="3oM_SD" id="2JTW8QYmJUn" role="1PaTwD">
-                  <property role="3oM_SC" value="not" />
-                </node>
-                <node concept="3oM_SD" id="2JTW8QYmJUq" role="1PaTwD">
-                  <property role="3oM_SC" value="always" />
-                </node>
-                <node concept="3oM_SD" id="2JTW8QYmJUA" role="1PaTwD">
-                  <property role="3oM_SC" value="correct" />
-                </node>
-                <node concept="3oM_SD" id="2JTW8QYmJVw" role="1PaTwD">
-                  <property role="3oM_SC" value="assert," />
-                </node>
-                <node concept="3oM_SD" id="2JTW8QYmJWZ" role="1PaTwD">
-                  <property role="3oM_SC" value="e.g." />
-                </node>
-                <node concept="3oM_SD" id="2JTW8QYmJXe" role="1PaTwD">
-                  <property role="3oM_SC" value="for" />
-                </node>
-                <node concept="3oM_SD" id="2JTW8QYmJXm" role="1PaTwD">
-                  <property role="3oM_SC" value="InstanceMethodCall" />
-                </node>
-              </node>
-            </node>
-            <node concept="3vFxKo" id="4t5t2tf9LFX" role="3cqZAp">
-              <node concept="2OqwBi" id="4t5t2tf9LFY" role="3vFALc">
-                <node concept="37vLTw" id="4t5t2tf9LFZ" role="2Oq$k0">
-                  <ref role="3cqZAo" node="4t5t2tf9LFu" resolve="typesDelta" />
-                </node>
-                <node concept="2Nt0df" id="4t5t2tf9LG0" role="2OqNvi">
-                  <node concept="2OqwBi" id="4t5t2tf9LG1" role="38cxEo">
-                    <node concept="liA8E" id="4t5t2tf9LG2" role="2OqNvi">
+            <node concept="3cpWs8" id="3xmq7qmRB39" role="3cqZAp">
+              <node concept="3cpWsn" id="3xmq7qmRB3c" role="3cpWs9">
+                <property role="TrG5h" value="failedType" />
+                <node concept="3Tqbb2" id="3xmq7qmRB37" role="1tU5fm" />
+                <node concept="3EllGN" id="3xmq7qmRCc_" role="33vP2m">
+                  <node concept="2OqwBi" id="3xmq7qmRCk1" role="3ElVtu">
+                    <node concept="liA8E" id="3xmq7qmRD5L" role="2OqNvi">
                       <ref role="37wK5l" to="mhbf:~SNode.getReference()" resolve="getReference" />
                     </node>
-                    <node concept="2JrnkZ" id="4t5t2tf9LG3" role="2Oq$k0">
-                      <node concept="37vLTw" id="4t5t2tf9LG4" role="2JrQYb">
+                    <node concept="2JrnkZ" id="3xmq7qmRCk6" role="2Oq$k0">
+                      <node concept="37vLTw" id="3xmq7qmRCdv" role="2JrQYb">
                         <ref role="3cqZAo" node="4t5t2tf9LEW" resolve="failingNode" />
                       </node>
                     </node>
                   </node>
+                  <node concept="37vLTw" id="3xmq7qmRB4X" role="3ElQJh">
+                    <ref role="3cqZAo" node="4t5t2tf9LFu" resolve="typesDelta" />
+                  </node>
+                </node>
+              </node>
+            </node>
+            <node concept="3vwNmj" id="3xmq7qmRKPK" role="3cqZAp">
+              <node concept="22lmx$" id="3xmq7qmRLq9" role="3vwVQn">
+                <node concept="2OqwBi" id="3xmq7qmRL$D" role="3uHU7w">
+                  <node concept="37vLTw" id="3xmq7qmRLtR" role="2Oq$k0">
+                    <ref role="3cqZAo" node="3xmq7qmRB3c" resolve="failedType" />
+                  </node>
+                  <node concept="1mIQ4w" id="3xmq7qmRLCT" role="2OqNvi">
+                    <node concept="chp4Y" id="3xmq7qmRLGB" role="cj9EA">
+                      <ref role="cht4Q" to="tpd4:hfSilrT" resolve="RuntimeErrorType" />
+                    </node>
+                  </node>
+                </node>
+                <node concept="2OqwBi" id="3xmq7qmRKV5" role="3uHU7B">
+                  <node concept="37vLTw" id="3xmq7qmRKPW" role="2Oq$k0">
+                    <ref role="3cqZAo" node="3xmq7qmRB3c" resolve="failedType" />
+                  </node>
+                  <node concept="3w_OXm" id="3xmq7qmRL3u" role="2OqNvi" />
                 </node>
               </node>
             </node>
diff --git a/samples/mpscore/solutions/typechecking.samples.baseLanguage/typechecking.samples.baseLanguage.msd b/samples/mpscore/solutions/typechecking.samples.baseLanguage/typechecking.samples.baseLanguage.msd
index 8e9f6e89..fa2613f2 100644
--- a/samples/mpscore/solutions/typechecking.samples.baseLanguage/typechecking.samples.baseLanguage.msd
+++ b/samples/mpscore/solutions/typechecking.samples.baseLanguage/typechecking.samples.baseLanguage.msd
@@ -15,6 +15,7 @@
     <dependency reexport="false">0fda14cc-a416-4c81-869a-2175d8b3325d(jetbrains.mps.baseLanguageExt)</dependency>
     <dependency reexport="false">bbf5c548-7111-4a53-a117-cdefc664cf34(jetbrains.mps.logic.reactor)</dependency>
     <dependency reexport="false">c4803b19-6d89-4a3b-bf82-390769514add(jetbrains.mps.lang.coderules)</dependency>
+    <dependency reexport="false">7a5dda62-9140-4668-ab76-d5ed1746f2b2(jetbrains.mps.lang.typesystem)</dependency>
   </dependencies>
   <languageVersions>
     <language slang="l:f3061a53-9226-4cc5-a443-f952ceaf5816:jetbrains.mps.baseLanguage" version="9" />
@@ -64,6 +65,7 @@
     <module reference="c72da2b9-7cce-4447-8389-f407dc1158b7(jetbrains.mps.lang.structure)" version="0" />
     <module reference="9ded098b-ad6a-4657-bfd9-48636cfe8bc3(jetbrains.mps.lang.traceable)" version="0" />
     <module reference="f486b8aa-5b2d-4ec0-8ef5-8f45d773fb84(jetbrains.mps.lang.typechecking.runtime)" version="0" />
+    <module reference="7a5dda62-9140-4668-ab76-d5ed1746f2b2(jetbrains.mps.lang.typesystem)" version="0" />
     <module reference="35320f26-77cb-4c55-be9f-a97a27770af1(jetbrains.mps.logic)" version="0" />
     <module reference="bbf5c548-7111-4a53-a117-cdefc664cf34(jetbrains.mps.logic.reactor)" version="0" />
     <module reference="a5478664-6b44-4c62-a9f7-434f8aa57eee(jetbrains.mps.logic.runtime)" version="0" />