diff --git a/samples/mpscore/languages/jetbrains.mps.baseLanguage.collectionsExt/models/jetbrains.mps.baseLanguage.collectionsExt.types.mps b/samples/mpscore/languages/jetbrains.mps.baseLanguage.collectionsExt/models/jetbrains.mps.baseLanguage.collectionsExt.types.mps
index e8496177..4aacf96d 100644
--- a/samples/mpscore/languages/jetbrains.mps.baseLanguage.collectionsExt/models/jetbrains.mps.baseLanguage.collectionsExt.types.mps
+++ b/samples/mpscore/languages/jetbrains.mps.baseLanguage.collectionsExt/models/jetbrains.mps.baseLanguage.collectionsExt.types.mps
@@ -24431,107 +24431,6 @@
     <property role="3GE5qa" value="rule.expression" />
     <property role="TrG5h" value="Expression" />
     <ref role="2YbDB9" to="kqnc:34$A1Mf51rY" resolve="TypeOf" />
-    <node concept="1nLNMY" id="3Z1xyIwqSo6" role="1nK1Vg">
-      <property role="TrG5h" value="downcastExpr" />
-      <node concept="3clFbS" id="3Z1xyIwqSo7" role="1nLNMH">
-        <node concept="3SKdUt" id="3Z1xyIwuLNy" role="3cqZAp">
-          <node concept="1PaTwC" id="3Z1xyIwuLNz" role="1aUNEU">
-            <node concept="3oM_SD" id="3Z1xyIwuLN$" role="1PaTwD">
-              <property role="3oM_SC" value="todo:" />
-            </node>
-            <node concept="3oM_SD" id="3Z1xyIwuLO6" role="1PaTwD">
-              <property role="3oM_SC" value="see" />
-            </node>
-            <node concept="3oM_SD" id="3Z1xyIw$cTf" role="1PaTwD">
-              <property role="3oM_SC" value="old" />
-            </node>
-            <node concept="3oM_SD" id="3Z1xyIw$cTj" role="1PaTwD">
-              <property role="3oM_SC" value="type" />
-            </node>
-            <node concept="3oM_SD" id="3Z1xyIw$cTo" role="1PaTwD">
-              <property role="3oM_SC" value="system" />
-            </node>
-            <node concept="3oM_SD" id="3Z1xyIw$cTu" role="1PaTwD">
-              <property role="3oM_SC" value="rule" />
-            </node>
-          </node>
-        </node>
-        <node concept="1nLNNL" id="3Z1xyIwqYwC" role="3cqZAp">
-          <node concept="1nLNMm" id="3Z1xyIwqYwD" role="1nLNNK">
-            <node concept="3Aq93q" id="3Z1xyIwr088" role="1nLNMb">
-              <property role="3ArMco" value="true" />
-              <node concept="3I6sU6" id="3Z1xyIwr089" role="3Ip0Jz">
-                <node concept="3I6s7M" id="3Z1xyIwr08d" role="3I6sU7">
-                  <node concept="3Aqt3T" id="3Z1xyIwr08c" role="3I6s78">
-                    <ref role="3AqCNq" to="kqnc:34$A1MfhdDv" resolve="typeOf" />
-                    <node concept="37jhX" id="3Z1xyIwr08k" role="3AunhB">
-                      <node concept="2OqwBi" id="3Z1xyIwr0fJ" role="37jj2">
-                        <node concept="3A2sRY" id="3Z1xyIwr08i" role="2Oq$k0">
-                          <ref role="3A2yKK" node="3Z1xyIwqYwj" resolve="expr" />
-                        </node>
-                        <node concept="3TrEf2" id="3Z1xyIwr0nW" role="2OqNvi">
-                          <ref role="3Tt5mk" to="tp2q:hRS9DVf" resolve="expression" />
-                        </node>
-                      </node>
-                    </node>
-                    <node concept="1HFMs5" id="3Z1xyIwsAmg" role="3AunhB">
-                      <node concept="a7P8L" id="3Z1xyIwr0qf" role="1uarlU">
-                        <ref role="a7OzE" node="3Z1xyIwqYwI" resolve="Expr" />
-                      </node>
-                      <node concept="ns1u0" id="3Z1xyIwsAmB" role="1uarlW">
-                        <ref role="ns1xF" to="kqnc:3Z1xyIvO9F3" resolve="runtimeType" />
-                        <node concept="nsMwS" id="3Z1xyIwsAmD" role="ns1xD">
-                          <ref role="nsMwP" to="kqnc:3Z1xyIvO9Gw" resolve="runtime" />
-                          <node concept="1nq8_$" id="3Z1xyIwsAnw" role="nsMwV">
-                            <node concept="a7P8L" id="3Z1xyIwsAnv" role="1nq8_t">
-                              <ref role="a7OzE" node="3Z1xyIwsAmH" resolve="RuntimeType" />
-                            </node>
-                          </node>
-                        </node>
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3NuqgR" id="3Z1xyIwqYwH" role="0Rg$4">
-              <node concept="aZer4" id="3Z1xyIwqYwI" role="3XD1gS">
-                <property role="TrG5h" value="Expr" />
-              </node>
-              <node concept="aZer4" id="3Z1xyIwsAmH" role="3XD1gS">
-                <property role="TrG5h" value="RuntimeType" />
-              </node>
-              <node concept="32pEOW" id="3Z1xyIwqYwU" role="3vLBG7" />
-            </node>
-            <node concept="3xSepi" id="3Z1xyIwr0qq" role="3xSepv">
-              <node concept="3Aq9E8" id="3Z1xyIwr0qr" role="3xSepj">
-                <node concept="3I6sU6" id="3Z1xyIwr0qs" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="3Z1xyIwsAnI" role="3I6sU7">
-                    <node concept="3Aqt3T" id="3Z1xyIwsAnH" role="3I6s78">
-                      <ref role="3AqCNq" to="kqnc:34$A1MfhdDv" resolve="typeOf" />
-                      <node concept="37jhX" id="3Z1xyIwsAnP" role="3AunhB">
-                        <node concept="3A2sRY" id="3Z1xyIwsAnN" role="37jj2">
-                          <ref role="3A2yKK" node="3Z1xyIwqYwj" resolve="expr" />
-                        </node>
-                      </node>
-                      <node concept="a7P8L" id="3Z1xyIwsAo5" role="3AunhB">
-                        <ref role="a7OzE" node="3Z1xyIwsAmH" resolve="RuntimeType" />
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-      <node concept="2t___k" id="3Z1xyIwqYwi" role="1nLNMg">
-        <ref role="2t_S0q" to="tp2q:hRS9umm" resolve="DowncastExpression" />
-        <node concept="3A20r5" id="3Z1xyIwqYwj" role="2t_VXX">
-          <property role="TrG5h" value="expr" />
-        </node>
-      </node>
-    </node>
     <node concept="1nLNMY" id="3Z1xyIwuJuP" role="1nK1Vg">
       <property role="TrG5h" value="mapAsSequenceVarRef" />
       <node concept="3clFbS" id="3Z1xyIwuJuQ" role="1nLNMH">
diff --git a/samples/mpscore/languages/jetbrains.mps.baseLanguageExt/models/jetbrains.mps.baseLanguageExt.types.mps b/samples/mpscore/languages/jetbrains.mps.baseLanguageExt/models/jetbrains.mps.baseLanguageExt.types.mps
index f868ee49..6646620d 100644
--- a/samples/mpscore/languages/jetbrains.mps.baseLanguageExt/models/jetbrains.mps.baseLanguageExt.types.mps
+++ b/samples/mpscore/languages/jetbrains.mps.baseLanguageExt/models/jetbrains.mps.baseLanguageExt.types.mps
@@ -13357,194 +13357,6 @@
         </node>
       </node>
     </node>
-    <node concept="1nLNMY" id="3MFPGC50D1T" role="1nK1Vg">
-      <property role="TrG5h" value="converts_runtimeType_classifier" />
-      <node concept="3clFbS" id="3MFPGC50D1U" role="1nLNMH">
-        <node concept="1nLNNL" id="3MFPGC50D1V" role="3cqZAp">
-          <node concept="1nLNMm" id="3MFPGC50D1W" role="1nLNNK">
-            <node concept="3Aq93q" id="3MFPGC50D1X" role="1nLNMb">
-              <node concept="3I6sU6" id="3MFPGC50D1Y" role="3Ip0Jz">
-                <node concept="3I6s7M" id="3MFPGC50D1Z" role="3I6sU7">
-                  <node concept="3Aqt3T" id="3MFPGC50D20" role="3I6s78">
-                    <ref role="3AqCNq" node="3vTJNooZDgN" resolve="convertsTo" />
-                    <node concept="1HFMs5" id="3MFPGC50D21" role="3AunhB">
-                      <node concept="a7P8L" id="3MFPGC50D22" role="1uarlU">
-                        <ref role="a7OzE" node="3MFPGC50D2f" resolve="T" />
-                      </node>
-                      <node concept="ns1u0" id="3MFPGC50D9n" role="1uarlW">
-                        <ref role="ns1xF" node="JOGAOsVt2a" resolve="classifier" />
-                      </node>
-                    </node>
-                    <node concept="1HFMs5" id="3MFPGC50D27" role="3AunhB">
-                      <node concept="a7P8L" id="3MFPGC50D28" role="1uarlU">
-                        <ref role="a7OzE" node="3MFPGC50D2e" resolve="S" />
-                      </node>
-                      <node concept="ns1u0" id="3Z1xyIvOeqd" role="1uarlW">
-                        <ref role="ns1xF" node="3Z1xyIvO9F3" resolve="runtimeType" />
-                        <node concept="nsMwS" id="3Z1xyIvOeqf" role="ns1xD">
-                          <ref role="nsMwP" node="3Z1xyIvO9Gw" resolve="runtime" />
-                          <node concept="1nq8_$" id="3Z1xyIvOers" role="nsMwV">
-                            <node concept="a7P8L" id="3Z1xyIvOerr" role="1nq8_t">
-                              <ref role="a7OzE" node="3MFPGC50D2g" resolve="RuntimeReprType" />
-                            </node>
-                          </node>
-                        </node>
-                      </node>
-                    </node>
-                    <node concept="a7P8L" id="4O7HczO3zP1" role="3AunhB">
-                      <ref role="a7OzE" node="4O7HczO3zOZ" resolve="Options" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3NuqgR" id="3MFPGC50D2d" role="0Rg$4">
-              <node concept="aZer4" id="3MFPGC50D2e" role="3XD1gS">
-                <property role="TrG5h" value="S" />
-              </node>
-              <node concept="aZer4" id="3MFPGC50D2f" role="3XD1gS">
-                <property role="TrG5h" value="T" />
-              </node>
-              <node concept="aZer4" id="3MFPGC50D2g" role="3XD1gS">
-                <property role="TrG5h" value="RuntimeReprType" />
-              </node>
-              <node concept="32pEOW" id="3MFPGC50D2i" role="3vLBG7" />
-            </node>
-            <node concept="3xSepi" id="3MFPGC50D2j" role="3xSepv">
-              <node concept="3Aq9E8" id="3MFPGC50D2k" role="3xSepj">
-                <node concept="3I6sU6" id="3MFPGC50D2l" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="3MFPGC50DX3" role="3I6sU7">
-                    <node concept="3Aqt3T" id="3MFPGC50DX2" role="3I6s78">
-                      <ref role="3AqCNq" node="3vTJNooZDgN" resolve="convertsTo" />
-                      <node concept="a7P8L" id="3MFPGC50DZl" role="3AunhB">
-                        <ref role="a7OzE" node="3MFPGC50D2f" resolve="T" />
-                      </node>
-                      <node concept="a7P8L" id="3Z1xyIvOeu1" role="3AunhB">
-                        <ref role="a7OzE" node="3MFPGC50D2g" resolve="RuntimeReprType" />
-                      </node>
-                      <node concept="a7P8L" id="4O7HczO3zP2" role="3AunhB">
-                        <ref role="a7OzE" node="4O7HczO3zOZ" resolve="Options" />
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3Aq9_M" id="3Z1xyIvVO2G" role="1nLNMa">
-              <node concept="3I6sU6" id="3Z1xyIvVO2H" role="3Ip0Jz">
-                <node concept="3I6s7M" id="3Z1xyIvVO3i" role="3I6sU7">
-                  <node concept="2aM9Np" id="3Z1xyIvVO3h" role="3I6s78">
-                    <node concept="a7P8L" id="3Z1xyIvVO3l" role="2aLmnP">
-                      <ref role="a7OzE" node="3MFPGC50D2g" resolve="RuntimeReprType" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3NuqgR" id="4O7HczO3zOX" role="0Rg$4">
-              <node concept="3uibUv" id="4O7HczO3zOY" role="3vLBG7">
-                <ref role="3uigEE" node="3vTJNooZBhQ" resolve="ConvertsContext.Options" />
-              </node>
-              <node concept="aZer4" id="4O7HczO3zOZ" role="3XD1gS">
-                <property role="TrG5h" value="Options" />
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbH" id="3MFPGC50F5O" role="3cqZAp" />
-        <node concept="1nLNNL" id="3MFPGC50F9P" role="3cqZAp">
-          <node concept="1nLNMm" id="3MFPGC50F9Q" role="1nLNNK">
-            <node concept="3Aq93q" id="3MFPGC50F9R" role="1nLNMb">
-              <node concept="3I6sU6" id="3MFPGC50F9S" role="3Ip0Jz">
-                <node concept="3I6s7M" id="3MFPGC50F9T" role="3I6sU7">
-                  <node concept="3Aqt3T" id="3MFPGC50F9U" role="3I6s78">
-                    <ref role="3AqCNq" node="3vTJNooZDgN" resolve="convertsTo" />
-                    <node concept="1HFMs5" id="3MFPGC50F9Y" role="3AunhB">
-                      <node concept="a7P8L" id="3MFPGC50FoC" role="1uarlU">
-                        <ref role="a7OzE" node="3MFPGC50Fa6" resolve="T" />
-                      </node>
-                      <node concept="ns1u0" id="3Z1xyIvOevC" role="1uarlW">
-                        <ref role="ns1xF" node="3Z1xyIvO9F3" resolve="runtimeType" />
-                        <node concept="nsMwS" id="3Z1xyIvOevD" role="ns1xD">
-                          <ref role="nsMwP" node="3Z1xyIvO9Gw" resolve="runtime" />
-                          <node concept="1nq8_$" id="3Z1xyIvOevE" role="nsMwV">
-                            <node concept="a7P8L" id="3Z1xyIvOevF" role="1nq8_t">
-                              <ref role="a7OzE" node="3Z1xyIvOeuS" resolve="RuntimeReprType" />
-                            </node>
-                          </node>
-                        </node>
-                      </node>
-                    </node>
-                    <node concept="1HFMs5" id="3MFPGC50FtO" role="3AunhB">
-                      <node concept="a7P8L" id="3MFPGC50FtM" role="1uarlU">
-                        <ref role="a7OzE" node="3MFPGC50Fa5" resolve="S" />
-                      </node>
-                      <node concept="ns1u0" id="3MFPGC50Fwi" role="1uarlW">
-                        <ref role="ns1xF" node="JOGAOsVt2a" resolve="classifier" />
-                      </node>
-                    </node>
-                    <node concept="a7P8L" id="4O7HczO3zPa" role="3AunhB">
-                      <ref role="a7OzE" node="4O7HczO3zP8" resolve="Options" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3NuqgR" id="3MFPGC50Fa4" role="0Rg$4">
-              <node concept="aZer4" id="3MFPGC50Fa5" role="3XD1gS">
-                <property role="TrG5h" value="S" />
-              </node>
-              <node concept="aZer4" id="3MFPGC50Fa6" role="3XD1gS">
-                <property role="TrG5h" value="T" />
-              </node>
-              <node concept="aZer4" id="3Z1xyIvOeuS" role="3XD1gS">
-                <property role="TrG5h" value="RuntimeReprType" />
-              </node>
-              <node concept="32pEOW" id="3MFPGC50Fa9" role="3vLBG7" />
-            </node>
-            <node concept="3xSepi" id="3MFPGC50Faa" role="3xSepv">
-              <node concept="3Aq9E8" id="3MFPGC50Fab" role="3xSepj">
-                <node concept="3I6sU6" id="3MFPGC50Fac" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="3MFPGC50Fad" role="3I6sU7">
-                    <node concept="3Aqt3T" id="3MFPGC50Fae" role="3I6s78">
-                      <ref role="3AqCNq" node="3vTJNooZDgN" resolve="convertsTo" />
-                      <node concept="a7P8L" id="3Z1xyIvOevY" role="3AunhB">
-                        <ref role="a7OzE" node="3Z1xyIvOeuS" resolve="RuntimeReprType" />
-                      </node>
-                      <node concept="a7P8L" id="3MFPGC52BAL" role="3AunhB">
-                        <ref role="a7OzE" node="3MFPGC50Fa5" resolve="S" />
-                      </node>
-                      <node concept="a7P8L" id="4O7HczO3zPb" role="3AunhB">
-                        <ref role="a7OzE" node="4O7HczO3zP8" resolve="Options" />
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3Aq9_M" id="3Z1xyIvVO3u" role="1nLNMa">
-              <node concept="3I6sU6" id="3Z1xyIvVO3v" role="3Ip0Jz">
-                <node concept="3I6s7M" id="3Z1xyIvVO3z" role="3I6sU7">
-                  <node concept="2aM9Np" id="3Z1xyIvVO3y" role="3I6s78">
-                    <node concept="a7P8L" id="3Z1xyIvVO3A" role="2aLmnP">
-                      <ref role="a7OzE" node="3Z1xyIvOeuS" resolve="RuntimeReprType" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3NuqgR" id="4O7HczO3zP6" role="0Rg$4">
-              <node concept="3uibUv" id="4O7HczO3zP7" role="3vLBG7">
-                <ref role="3uigEE" node="3vTJNooZBhQ" resolve="ConvertsContext.Options" />
-              </node>
-              <node concept="aZer4" id="4O7HczO3zP8" role="3XD1gS">
-                <property role="TrG5h" value="Options" />
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-    </node>
     <node concept="1nLNMY" id="12QmIo_7sik" role="1nK1Vg">
       <property role="TrG5h" value="converts_classifier_to_classifier" />
       <node concept="3clFbS" id="12QmIo_7sil" role="1nLNMH">
@@ -42189,15 +42001,6 @@
       <property role="3uGXoX" value="true" />
       <node concept="nspSf" id="4lCLOtwq2MG" role="ns1xx" />
     </node>
-    <node concept="ns1x$" id="3Z1xyIvO9F3" role="ns1xc">
-      <property role="TrG5h" value="runtimeType" />
-      <ref role="ns1xW" node="4lCLOtwq2MF" resolve="type" />
-      <node concept="nspSf" id="3Z1xyIvO9F4" role="ns1xx">
-        <node concept="nstbe" id="3Z1xyIvO9Gw" role="nspSe">
-          <property role="TrG5h" value="runtime" />
-        </node>
-      </node>
-    </node>
     <node concept="ns1x$" id="ZJPHcupkhk" role="ns1xc">
       <property role="TrG5h" value="parameterized" />
       <property role="3uGXoX" value="true" />