diff --git a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.base/models/editor.mps b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.base/models/editor.mps
index 08d742f091..9ab1c45d93 100755
--- a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.base/models/editor.mps
+++ b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.base/models/editor.mps
@@ -2151,24 +2151,6 @@
       <node concept="3F0ifn" id="1Ez$z58Hu8o" role="3EZMnx">
         <property role="3F0ifm" value="error" />
         <ref role="1k5W1q" to="itrz:4rZeNQ6MfR7" resolve="iets3Keyword" />
-        <node concept="11LMrY" id="1Ez$z58IP7n" role="3F10Kt">
-          <property role="VOm3f" value="true" />
-          <node concept="3nzxsE" id="1Ez$z58IP7q" role="3n$kyP">
-            <node concept="3clFbS" id="1Ez$z58IP7r" role="2VODD2">
-              <node concept="3clFbF" id="1Ez$z58IP84" role="3cqZAp">
-                <node concept="3y3z36" id="1Ez$z58IPno" role="3clFbG">
-                  <node concept="10Nm6u" id="1Ez$z58IPoy" role="3uHU7w" />
-                  <node concept="2OqwBi" id="1Ez$z58IPaF" role="3uHU7B">
-                    <node concept="pncrf" id="1Ez$z58IP83" role="2Oq$k0" />
-                    <node concept="3TrEf2" id="1Ez$z58IPg3" role="2OqNvi">
-                      <ref role="3Tt5mk" to="hm2y:1Ez$z58Hu7L" resolve="error" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
       </node>
       <node concept="_tjkj" id="1Ez$z58Hu8B" role="3EZMnx">
         <node concept="3EZMnI" id="1Ez$z58Hu8L" role="_tjki">
@@ -2194,6 +2176,9 @@
           <node concept="VPM3Z" id="1Ez$z58Hu8P" role="3F10Kt">
             <property role="VOm3f" value="false" />
           </node>
+          <node concept="11L4FC" id="7JKsSwYyQXa" role="3F10Kt">
+            <property role="VOm3f" value="true" />
+          </node>
         </node>
       </node>
       <node concept="2iRfu4" id="1Ez$z58Hu8h" role="2iSdaV" />
@@ -4589,9 +4574,6 @@
       <node concept="3F0ifn" id="mQGcCvPufx" role="3EZMnx">
         <property role="3F0ifm" value="fail" />
         <ref role="1k5W1q" to="itrz:4rZeNQ6MfR7" resolve="iets3Keyword" />
-        <node concept="11LMrY" id="6jT4GDwsanM" role="3F10Kt">
-          <property role="VOm3f" value="true" />
-        </node>
       </node>
       <node concept="_tjkj" id="6jT4GDw7eTM" role="3EZMnx">
         <node concept="3EZMnI" id="6jT4GDw7eSK" role="_tjki">
diff --git a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.messages/models/structure.mps b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.messages/models/structure.mps
index 1ee38a8081..010864f8e6 100644
--- a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.messages/models/structure.mps
+++ b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.messages/models/structure.mps
@@ -216,13 +216,12 @@
     <property role="R4oN_" value="a message argument" />
     <ref role="1TJDcQ" to="tpck:gw2VY9q" resolve="BaseConcept" />
     <node concept="PrWs8" id="3vxfdxbdUeE" role="PzmwI">
-      <ref role="PrY4T" to="tpck:h0TrEE$" resolve="INamedConcept" />
+      <ref role="PrY4T" to="4kwy:cJpacq5T0O" resolve="IValidNamedConcept" />
     </node>
     <node concept="1TJgyj" id="3vxfdxbdUeH" role="1TKVEi">
       <property role="IQ2ns" value="4026566441518474157" />
       <property role="20lmBu" value="fLJjDmT/aggregation" />
       <property role="20kJfa" value="type" />
-      <property role="20lbJX" value="fLJekj4/_1" />
       <ref role="20lvS9" to="hm2y:6sdnDbSlaok" resolve="Type" />
     </node>
   </node>
diff --git a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.mutable/models/behavior.mps b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.mutable/models/behavior.mps
index 8138921477..07a907d07f 100644
--- a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.mutable/models/behavior.mps
+++ b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.mutable/models/behavior.mps
@@ -1664,9 +1664,12 @@
     <node concept="13i0hz" id="4IV0h47jS3m" role="13h7CS">
       <property role="TrG5h" value="expectedType" />
       <property role="13i0it" value="true" />
-      <property role="13i0iv" value="true" />
       <node concept="3Tm1VV" id="4IV0h47jS3n" role="1B3o_S" />
-      <node concept="3clFbS" id="4IV0h47jS3p" role="3clF47" />
+      <node concept="3clFbS" id="4IV0h47jS3p" role="3clF47">
+        <node concept="3clFbF" id="7JKsSwYB5ZH" role="3cqZAp">
+          <node concept="10Nm6u" id="7JKsSwYB5ZG" role="3clFbG" />
+        </node>
+      </node>
       <node concept="3Tqbb2" id="4IV0h47Eqok" role="3clF45">
         <ref role="ehGHo" to="hm2y:6sdnDbSlaok" resolve="Type" />
       </node>
diff --git a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.simpleTypes/models/behavior.mps b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.simpleTypes/models/behavior.mps
index f2bea080fc..f594b222ee 100755
--- a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.simpleTypes/models/behavior.mps
+++ b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.simpleTypes/models/behavior.mps
@@ -99,9 +99,6 @@
       <concept id="1081236700937" name="jetbrains.mps.baseLanguage.structure.StaticMethodCall" flags="nn" index="2YIFZM">
         <reference id="1144433194310" name="classConcept" index="1Pybhc" />
       </concept>
-      <concept id="1164991038168" name="jetbrains.mps.baseLanguage.structure.ThrowStatement" flags="nn" index="YS8fn">
-        <child id="1164991057263" name="throwable" index="YScLw" />
-      </concept>
       <concept id="1070533707846" name="jetbrains.mps.baseLanguage.structure.StaticFieldReference" flags="nn" index="10M0yZ">
         <reference id="1144433057691" name="classifier" index="1PxDUh" />
       </concept>
@@ -241,6 +238,12 @@
         <child id="8182547171709752112" name="expression" index="36biLW" />
       </concept>
     </language>
+    <language id="760a0a8c-eabb-4521-8bfd-65db761a9ba3" name="jetbrains.mps.baseLanguage.logging">
+      <concept id="2034914114981261497" name="jetbrains.mps.baseLanguage.logging.structure.LogLowLevelStatement" flags="ng" index="RRSsy">
+        <property id="2034914114981261751" name="severity" index="RRSoG" />
+        <child id="2034914114981261753" name="message" index="RRSoy" />
+      </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" />
@@ -5266,14 +5269,10 @@
       <node concept="3clFbS" id="7Wa2sv3EZOx" role="3clF47">
         <node concept="3clFbJ" id="3z1zSuyKmFc" role="3cqZAp">
           <node concept="3clFbS" id="3z1zSuyKmFe" role="3clFbx">
-            <node concept="YS8fn" id="3z1zSuyKnAM" role="3cqZAp">
-              <node concept="2ShNRf" id="3z1zSuyKnB8" role="YScLw">
-                <node concept="1pGfFk" id="3z1zSuyKoRx" role="2ShVmc">
-                  <ref role="37wK5l" to="wyt6:~IllegalArgumentException.&lt;init&gt;(java.lang.String)" resolve="IllegalArgumentException" />
-                  <node concept="Xl_RD" id="3z1zSuyKoUv" role="37wK5m">
-                    <property role="Xl_RC" value="Negative number precision is not allowed" />
-                  </node>
-                </node>
+            <node concept="RRSsy" id="7JKsSwYB_2j" role="3cqZAp">
+              <property role="RRSoG" value="gZ5fksE/warn" />
+              <node concept="Xl_RD" id="7JKsSwYB_2l" role="RRSoy">
+                <property role="Xl_RC" value="Negative number precision is not allowed" />
               </node>
             </node>
           </node>
@@ -5285,21 +5284,25 @@
               <ref role="3cqZAo" node="7Wa2sv3F02P" resolve="p" />
             </node>
           </node>
-        </node>
-        <node concept="3clFbF" id="7Wa2sv3F03e" role="3cqZAp">
-          <node concept="37vLTI" id="7Wa2sv3F0zj" role="3clFbG">
-            <node concept="3cpWs3" id="7Wa2sv3F1Pt" role="37vLTx">
-              <node concept="Xl_RD" id="7Wa2sv3F1Pw" role="3uHU7w">
-                <property role="Xl_RC" value="" />
-              </node>
-              <node concept="37vLTw" id="7Wa2sv3F0z_" role="3uHU7B">
-                <ref role="3cqZAo" node="7Wa2sv3F02P" resolve="p" />
-              </node>
-            </node>
-            <node concept="2OqwBi" id="7Wa2sv3F08C" role="37vLTJ">
-              <node concept="13iPFW" id="7Wa2sv3F03d" role="2Oq$k0" />
-              <node concept="3TrcHB" id="7Wa2sv3F0eI" role="2OqNvi">
-                <ref role="3TsBF5" to="5qo5:19PglA20qY6" resolve="prec" />
+          <node concept="9aQIb" id="7JKsSwYB_h_" role="9aQIa">
+            <node concept="3clFbS" id="7JKsSwYB_hA" role="9aQI4">
+              <node concept="3clFbF" id="7Wa2sv3F03e" role="3cqZAp">
+                <node concept="37vLTI" id="7Wa2sv3F0zj" role="3clFbG">
+                  <node concept="3cpWs3" id="7Wa2sv3F1Pt" role="37vLTx">
+                    <node concept="Xl_RD" id="7Wa2sv3F1Pw" role="3uHU7w">
+                      <property role="Xl_RC" value="" />
+                    </node>
+                    <node concept="37vLTw" id="7Wa2sv3F0z_" role="3uHU7B">
+                      <ref role="3cqZAo" node="7Wa2sv3F02P" resolve="p" />
+                    </node>
+                  </node>
+                  <node concept="2OqwBi" id="7Wa2sv3F08C" role="37vLTJ">
+                    <node concept="13iPFW" id="7Wa2sv3F03d" role="2Oq$k0" />
+                    <node concept="3TrcHB" id="7Wa2sv3F0eI" role="2OqNvi">
+                      <ref role="3TsBF5" to="5qo5:19PglA20qY6" resolve="prec" />
+                    </node>
+                  </node>
+                </node>
               </node>
             </node>
           </node>
diff --git a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.toplevel/models/org/iets3/core/expr/toplevel/editor.mps b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.toplevel/models/org/iets3/core/expr/toplevel/editor.mps
index dbe5b781a5..50f576bfba 100755
--- a/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.toplevel/models/org/iets3/core/expr/toplevel/editor.mps
+++ b/code/languages/org.iets3.opensource/languages/org.iets3.core.expr.toplevel/models/org/iets3/core/expr/toplevel/editor.mps
@@ -1765,13 +1765,13 @@
                   <property role="VOm3f" value="true" />
                 </node>
               </node>
-              <node concept="l2Vlx" id="3WWvqarUH$5" role="2iSdaV" />
               <node concept="VPM3Z" id="3WWvqarUH$6" role="3F10Kt">
                 <property role="VOm3f" value="false" />
               </node>
               <node concept="11L4FC" id="3WWvqarUH$7" role="3F10Kt">
                 <property role="VOm3f" value="true" />
               </node>
+              <node concept="l2Vlx" id="3WWvqarUH$5" role="2iSdaV" />
             </node>
           </node>
           <node concept="3F0ifn" id="3WWvqarUJIZ" role="3EZMnx">
@@ -1899,13 +1899,6 @@
                 <property role="VOm3f" value="true" />
               </node>
             </node>
-            <node concept="ZYGn8" id="68WOIGeG1Ja" role="ZWbT9">
-              <node concept="3clFbS" id="68WOIGeG1Jb" role="2VODD2">
-                <node concept="3clFbF" id="68WOIGeG1Jl" role="3cqZAp">
-                  <node concept="10Nm6u" id="68WOIGeG1Jk" role="3clFbG" />
-                </node>
-              </node>
-            </node>
           </node>
           <node concept="3F0ifn" id="3YhAT14YvNu" role="3EZMnx">
             <property role="3F0ifm" value="{..}" />
@@ -1968,6 +1961,7 @@
             </node>
           </node>
         </node>
+        <node concept="l2Vlx" id="3WWvqarUGzE" role="2iSdaV" />
         <node concept="_tjkj" id="3WWvqarUGzv" role="3EZMnx">
           <node concept="3EZMnI" id="3WWvqarUGzw" role="_tjki">
             <node concept="3F0ifn" id="3WWvqarUGzx" role="3EZMnx">
@@ -1988,23 +1982,15 @@
                 <property role="VOm3f" value="true" />
               </node>
             </node>
-            <node concept="l2Vlx" id="3WWvqarUGzB" role="2iSdaV" />
             <node concept="VPM3Z" id="3WWvqarUGzC" role="3F10Kt">
               <property role="VOm3f" value="false" />
             </node>
             <node concept="11L4FC" id="3WWvqarUGzD" role="3F10Kt">
               <property role="VOm3f" value="true" />
             </node>
-          </node>
-          <node concept="ZYGn8" id="68WOIGeG1KK" role="ZWbT9">
-            <node concept="3clFbS" id="68WOIGeG1KL" role="2VODD2">
-              <node concept="3clFbF" id="68WOIGeG1KV" role="3cqZAp">
-                <node concept="10Nm6u" id="68WOIGeG1KU" role="3clFbG" />
-              </node>
-            </node>
+            <node concept="l2Vlx" id="3WWvqarUGzB" role="2iSdaV" />
           </node>
         </node>
-        <node concept="l2Vlx" id="3WWvqarUGzE" role="2iSdaV" />
         <node concept="3F0ifn" id="3WWvqarUGzF" role="3EZMnx">
           <property role="3F0ifm" value="{" />
         </node>
@@ -2224,13 +2210,6 @@
                 <property role="VOm3f" value="true" />
               </node>
             </node>
-            <node concept="ZYGn8" id="68WOIGeKJyS" role="ZWbT9">
-              <node concept="3clFbS" id="68WOIGeKJyT" role="2VODD2">
-                <node concept="3clFbF" id="68WOIGeKJz$" role="3cqZAp">
-                  <node concept="10Nm6u" id="68WOIGeKJzz" role="3clFbG" />
-                </node>
-              </node>
-            </node>
           </node>
           <node concept="2iRfu4" id="3YhAT14Yx9m" role="2iSdaV" />
           <node concept="VPM3Z" id="3YhAT14Yx9n" role="3F10Kt">