diff --git a/samples/fitch/languages/jetbrains.mps.fitch/jetbrains.mps.fitch.mpl b/samples/fitch/languages/jetbrains.mps.fitch/jetbrains.mps.fitch.mpl
index 92538dc0..9ccdc665 100644
--- a/samples/fitch/languages/jetbrains.mps.fitch/jetbrains.mps.fitch.mpl
+++ b/samples/fitch/languages/jetbrains.mps.fitch/jetbrains.mps.fitch.mpl
@@ -56,6 +56,7 @@
     <language slang="l:daafa647-f1f7-4b0b-b096-69cd7c8408c0:jetbrains.mps.baseLanguage.regexp" version="0" />
     <language slang="l:a247e09e-2435-45ba-b8d2-07e93feba96a:jetbrains.mps.baseLanguage.tuples" version="0" />
     <language slang="l:df345b11-b8c7-4213-ac66-48d2a9b75d88:jetbrains.mps.baseLanguageInternal" version="0" />
+    <language slang="l:942985d5-7bcf-46ee-8b79-7b662eaebb4e:jetbrains.mps.dataform" version="0" />
     <language slang="l:aee9cad2-acd4-4608-aef2-0004f6a1cdbd:jetbrains.mps.lang.actions" version="4" />
     <language slang="l:af65afd8-f0dd-4942-87d9-63a55f2a9db1:jetbrains.mps.lang.behavior" version="1" />
     <language slang="l:fe9d76d7-5809-45c9-ae28-a40915b4d6ff:jetbrains.mps.lang.checkedName" version="0" />
diff --git a/samples/fitch/languages/jetbrains.mps.fitch/models/types.mps b/samples/fitch/languages/jetbrains.mps.fitch/models/types.mps
index d24ff940..fe515214 100644
--- a/samples/fitch/languages/jetbrains.mps.fitch/models/types.mps
+++ b/samples/fitch/languages/jetbrains.mps.fitch/models/types.mps
@@ -4,6 +4,7 @@
   <languages>
     <use id="c4803b19-6d89-4a3b-bf82-390769514add" name="jetbrains.mps.lang.typesystem2" version="13" />
     <use id="f3061a53-9226-4cc5-a443-f952ceaf5816" name="jetbrains.mps.baseLanguage" version="6" />
+    <use id="942985d5-7bcf-46ee-8b79-7b662eaebb4e" name="jetbrains.mps.dataform" version="0" />
     <devkit ref="2677cb18-f558-4e33-bc38-a5139cee06dc(jetbrains.mps.devkit.language-design)" />
   </languages>
   <imports>
diff --git a/samples/fitch/languages/jetbrains.mps.logic.firstOrder/jetbrains.mps.logic.firstOrder.mpl b/samples/fitch/languages/jetbrains.mps.logic.firstOrder/jetbrains.mps.logic.firstOrder.mpl
index 62d51353..e43bb173 100644
--- a/samples/fitch/languages/jetbrains.mps.logic.firstOrder/jetbrains.mps.logic.firstOrder.mpl
+++ b/samples/fitch/languages/jetbrains.mps.logic.firstOrder/jetbrains.mps.logic.firstOrder.mpl
@@ -62,6 +62,7 @@
     <language slang="l:760a0a8c-eabb-4521-8bfd-65db761a9ba3:jetbrains.mps.baseLanguage.logging" version="0" />
     <language slang="l:a247e09e-2435-45ba-b8d2-07e93feba96a:jetbrains.mps.baseLanguage.tuples" version="0" />
     <language slang="l:df345b11-b8c7-4213-ac66-48d2a9b75d88:jetbrains.mps.baseLanguageInternal" version="0" />
+    <language slang="l:942985d5-7bcf-46ee-8b79-7b662eaebb4e:jetbrains.mps.dataform" version="0" />
     <language slang="l:aee9cad2-acd4-4608-aef2-0004f6a1cdbd:jetbrains.mps.lang.actions" version="4" />
     <language slang="l:af65afd8-f0dd-4942-87d9-63a55f2a9db1:jetbrains.mps.lang.behavior" version="1" />
     <language slang="l:fe9d76d7-5809-45c9-ae28-a40915b4d6ff:jetbrains.mps.lang.checkedName" version="0" />
diff --git a/samples/fitch/languages/jetbrains.mps.logic.firstOrder/models/types.mps b/samples/fitch/languages/jetbrains.mps.logic.firstOrder/models/types.mps
index d3ccfd82..57abdaaf 100644
--- a/samples/fitch/languages/jetbrains.mps.logic.firstOrder/models/types.mps
+++ b/samples/fitch/languages/jetbrains.mps.logic.firstOrder/models/types.mps
@@ -3,6 +3,7 @@
   <persistence version="9" />
   <languages>
     <use id="c4803b19-6d89-4a3b-bf82-390769514add" name="jetbrains.mps.lang.typesystem2" version="13" />
+    <use id="942985d5-7bcf-46ee-8b79-7b662eaebb4e" name="jetbrains.mps.dataform" version="0" />
     <devkit ref="2677cb18-f558-4e33-bc38-a5139cee06dc(jetbrains.mps.devkit.language-design)" />
   </languages>
   <imports>
@@ -230,6 +231,7 @@
         <child id="4340821131304055573" name="condition" index="30RCb4" />
       </concept>
       <concept id="8335224865066015764" name="jetbrains.mps.lang.typesystem2.structure.Handler" flags="ng" index="AVZre">
+        <reference id="3541122455446356437" name="extends" index="2YbDB9" />
         <child id="7368070394767441299" name="rule" index="3ArX_J" />
       </concept>
       <concept id="6678105047444342713" name="jetbrains.mps.lang.typesystem2.structure.RuleParameterDeclaration" flags="ng" index="391aah">
@@ -439,7 +441,8 @@
     </node>
   </node>
   <node concept="AVZre" id="3w0n0hzm35U">
-    <property role="TrG5h" value="Reasoning" />
+    <property role="TrG5h" value="FOReasoning" />
+    <ref role="2YbDB9" to="6r1k:5RfK0kxl_zr" resolve="Reasoning" />
     <node concept="AVZhu" id="3w0n0hzmfJv" role="3ArX_J">
       <property role="TrG5h" value="equalityIntroConclusion" />
       <node concept="3Aq9E8" id="3w0n0hzmfKd" role="3otmyu">
diff --git a/samples/fitch/languages/jetbrains.mps.logic.propositional/jetbrains.mps.logic.propositional.mpl b/samples/fitch/languages/jetbrains.mps.logic.propositional/jetbrains.mps.logic.propositional.mpl
index 3e7a6d6a..7afcebdf 100644
--- a/samples/fitch/languages/jetbrains.mps.logic.propositional/jetbrains.mps.logic.propositional.mpl
+++ b/samples/fitch/languages/jetbrains.mps.logic.propositional/jetbrains.mps.logic.propositional.mpl
@@ -60,6 +60,7 @@
     <language slang="l:daafa647-f1f7-4b0b-b096-69cd7c8408c0:jetbrains.mps.baseLanguage.regexp" version="0" />
     <language slang="l:a247e09e-2435-45ba-b8d2-07e93feba96a:jetbrains.mps.baseLanguage.tuples" version="0" />
     <language slang="l:df345b11-b8c7-4213-ac66-48d2a9b75d88:jetbrains.mps.baseLanguageInternal" version="0" />
+    <language slang="l:942985d5-7bcf-46ee-8b79-7b662eaebb4e:jetbrains.mps.dataform" version="0" />
     <language slang="l:aee9cad2-acd4-4608-aef2-0004f6a1cdbd:jetbrains.mps.lang.actions" version="4" />
     <language slang="l:af65afd8-f0dd-4942-87d9-63a55f2a9db1:jetbrains.mps.lang.behavior" version="1" />
     <language slang="l:fe9d76d7-5809-45c9-ae28-a40915b4d6ff:jetbrains.mps.lang.checkedName" version="0" />
diff --git a/samples/fitch/languages/jetbrains.mps.logic.propositional/models/types.mps b/samples/fitch/languages/jetbrains.mps.logic.propositional/models/types.mps
index ad24bc65..95272fd5 100644
--- a/samples/fitch/languages/jetbrains.mps.logic.propositional/models/types.mps
+++ b/samples/fitch/languages/jetbrains.mps.logic.propositional/models/types.mps
@@ -7,6 +7,7 @@
     <use id="7866978e-a0f0-4cc7-81bc-4d213d9375e1" name="jetbrains.mps.lang.smodel" version="11" />
     <use id="35320f26-77cb-4c55-be9f-a97a27770af1" name="jetbrains.mps.logic" version="2" />
     <use id="83888646-71ce-4f1c-9c53-c54016f6ad4f" name="jetbrains.mps.baseLanguage.collections" version="0" />
+    <use id="942985d5-7bcf-46ee-8b79-7b662eaebb4e" name="jetbrains.mps.dataform" version="0" />
     <devkit ref="2677cb18-f558-4e33-bc38-a5139cee06dc(jetbrains.mps.devkit.language-design)" />
   </languages>
   <imports>
@@ -192,6 +193,7 @@
         <child id="4340821131304055573" name="condition" index="30RCb4" />
       </concept>
       <concept id="8335224865066015764" name="jetbrains.mps.lang.typesystem2.structure.Handler" flags="ng" index="AVZre">
+        <reference id="3541122455446356437" name="extends" index="2YbDB9" />
         <child id="1980609059185345194" name="constraint" index="8PkJo" />
         <child id="7368070394767441299" name="rule" index="3ArX_J" />
       </concept>
@@ -821,7 +823,8 @@
     </node>
   </node>
   <node concept="AVZre" id="5RfK0kxl_zr">
-    <property role="TrG5h" value="Reasoning" />
+    <property role="TrG5h" value="PropReasoning" />
+    <ref role="2YbDB9" to="f3ld:2aBGSFge0GD" resolve="Check" />
     <node concept="AVZhu" id="2aBGSFgfACW" role="3ArX_J">
       <property role="TrG5h" value="Judgement_conclusion" />
       <node concept="3Aq9E8" id="2aBGSFgfAEo" role="3otmyu">