diff --git a/samples/lambdacalc/languages/sample.fooblin/models/editor.mps b/samples/lambdacalc/languages/sample.fooblin/models/editor.mps
index fcac7c0d..f34cbf12 100644
--- a/samples/lambdacalc/languages/sample.fooblin/models/editor.mps
+++ b/samples/lambdacalc/languages/sample.fooblin/models/editor.mps
@@ -789,5 +789,15 @@
       <node concept="l2Vlx" id="12dHl3ZCFa$" role="2iSdaV" />
     </node>
   </node>
+  <node concept="24kQdi" id="1z4HGmnV7KW">
+    <property role="3GE5qa" value="expr" />
+    <ref role="1XX52x" to="8tt8:1z4HGmnV7K8" resolve="Fix" />
+    <node concept="3EZMnI" id="1z4HGmnV7Lm" role="2wV5jI">
+      <node concept="PMmxH" id="1z4HGmnV7Lz" role="3EZMnx">
+        <ref role="PMmxG" to="tpco:2wZex4PafBj" resolve="alias" />
+      </node>
+      <node concept="l2Vlx" id="1z4HGmnV7Lp" role="2iSdaV" />
+    </node>
+  </node>
 </model>
 
diff --git a/samples/lambdacalc/languages/sample.fooblin/models/structure.mps b/samples/lambdacalc/languages/sample.fooblin/models/structure.mps
index e7cb6eeb..85b1e1de 100644
--- a/samples/lambdacalc/languages/sample.fooblin/models/structure.mps
+++ b/samples/lambdacalc/languages/sample.fooblin/models/structure.mps
@@ -315,5 +315,12 @@
       <ref role="20lvS9" node="3_qfG1EP6Nw" resolve="Type" />
     </node>
   </node>
+  <node concept="1TIwiD" id="1z4HGmnV7K8">
+    <property role="EcuMT" value="1784752312119229448" />
+    <property role="3GE5qa" value="expr" />
+    <property role="TrG5h" value="Fix" />
+    <property role="34LRSv" value="fix" />
+    <ref role="1TJDcQ" node="7_8aRkgDGPJ" resolve="Expr" />
+  </node>
 </model>
 
diff --git a/samples/lambdacalc/languages/sample.fooblin/models/types.mps b/samples/lambdacalc/languages/sample.fooblin/models/types.mps
index e7056b32..5410e26e 100644
--- a/samples/lambdacalc/languages/sample.fooblin/models/types.mps
+++ b/samples/lambdacalc/languages/sample.fooblin/models/types.mps
@@ -1255,6 +1255,119 @@
         </node>
       </node>
     </node>
+    <node concept="AVZhu" id="1YCbHn1AJsC" role="3ArX_J">
+      <property role="TrG5h" value="typeOf_Fix" />
+      <node concept="2t___k" id="1YCbHn1AJ$O" role="20_v8_">
+        <ref role="2t_S0q" to="8tt8:1z4HGmnV7K8" resolve="Fix" />
+        <node concept="3A20r5" id="1YCbHn1AJ$P" role="2t_VXX">
+          <property role="TrG5h" value="fix" />
+        </node>
+      </node>
+      <node concept="3Aq9E8" id="1YCbHn1AJPl" role="3otmyu">
+        <node concept="3I6sU6" id="1YCbHn1AJPm" role="3Ip0Jz">
+          <node concept="3I6s7M" id="1YCbHn1AQkJ" role="3I6sU7">
+            <node concept="3A8Hvi" id="1YCbHn1AQkD" role="3I6s78">
+              <node concept="a7P8L" id="1YCbHn1AQnZ" role="3A8wtg">
+                <ref role="a7OzE" node="1YCbHn1AQkt" resolve="F" />
+              </node>
+              <node concept="1Q4cc8" id="1YCbHn1AKBY" role="3A8w4Q">
+                <ref role="1nfQt" node="12dHl3ZCxN1" resolve="Forall" />
+                <node concept="1RziaG" id="1YCbHn1AKC2" role="1Ryyee">
+                  <ref role="1RzibV" node="12dHl3ZCEvq" resolve="type" />
+                  <node concept="3AP2Rn" id="1YCbHn1AKC3" role="1RzmR7">
+                    <node concept="3clFbS" id="1YCbHn1AKC4" role="16YjZG">
+                      <node concept="3clFbF" id="1YCbHn1AKCj" role="3cqZAp">
+                        <node concept="3A9UF8" id="1YCbHn1AKCh" role="3clFbG">
+                          <node concept="1Q4cc8" id="1YCbHn1AKDc" role="3A9W3M">
+                            <ref role="1nfQt" node="4dPZ2m2hWGK" resolve="Fun" />
+                            <node concept="1RziaG" id="1YCbHn1AKEd" role="1Ryyee">
+                              <ref role="1RzibV" node="4dPZ2m2hXGZ" resolve="arg" />
+                              <node concept="3AP2Rn" id="1YCbHn1AKEe" role="1RzmR7">
+                                <node concept="3clFbS" id="1YCbHn1AKEf" role="16YjZG">
+                                  <node concept="3clFbF" id="1YCbHn1AKG6" role="3cqZAp">
+                                    <node concept="3A9UF8" id="1YCbHn1AKG4" role="3clFbG">
+                                      <node concept="1Q4cc8" id="1YCbHn1AKGZ" role="3A9W3M">
+                                        <ref role="1nfQt" node="4dPZ2m2hWGK" resolve="Fun" />
+                                        <node concept="1RziaG" id="1YCbHn1AKIF" role="1Ryyee">
+                                          <ref role="1RzibV" node="4dPZ2m2hXGZ" resolve="arg" />
+                                          <node concept="3AP2Rn" id="1YCbHn1AKIG" role="1RzmR7">
+                                            <node concept="3clFbS" id="1YCbHn1AKIH" role="16YjZG">
+                                              <node concept="3clFbF" id="1YCbHn1AKKJ" role="3cqZAp">
+                                                <node concept="3A9UF8" id="1YCbHn1AKKH" role="3clFbG">
+                                                  <node concept="a7P8L" id="1YCbHn1AKKX" role="3A9W3M">
+                                                    <ref role="a7OzE" node="1YCbHn1AKJT" resolve="A" />
+                                                  </node>
+                                                </node>
+                                              </node>
+                                            </node>
+                                          </node>
+                                        </node>
+                                        <node concept="1RziaG" id="1YCbHn1AKRQ" role="1Ryyee">
+                                          <ref role="1RzibV" node="4dPZ2m2hXHj" resolve="res" />
+                                          <node concept="3AP2Rn" id="1YCbHn1AKRR" role="1RzmR7">
+                                            <node concept="3clFbS" id="1YCbHn1AKRS" role="16YjZG">
+                                              <node concept="3clFbF" id="1YCbHn1AKTP" role="3cqZAp">
+                                                <node concept="3A9UF8" id="1YCbHn1AKTN" role="3clFbG">
+                                                  <node concept="a7P8L" id="1YCbHn1AKU3" role="3A9W3M">
+                                                    <ref role="a7OzE" node="1YCbHn1AKJT" resolve="A" />
+                                                  </node>
+                                                </node>
+                                              </node>
+                                            </node>
+                                          </node>
+                                        </node>
+                                      </node>
+                                    </node>
+                                  </node>
+                                </node>
+                              </node>
+                            </node>
+                            <node concept="1RziaG" id="1YCbHn1AKY8" role="1Ryyee">
+                              <ref role="1RzibV" node="4dPZ2m2hXHj" resolve="res" />
+                              <node concept="3AP2Rn" id="1YCbHn1AKY9" role="1RzmR7">
+                                <node concept="3clFbS" id="1YCbHn1AKYa" role="16YjZG">
+                                  <node concept="3clFbF" id="1YCbHn1AL0j" role="3cqZAp">
+                                    <node concept="3A9UF8" id="1YCbHn1AL0h" role="3clFbG">
+                                      <node concept="a7P8L" id="1YCbHn1AL1c" role="3A9W3M">
+                                        <ref role="a7OzE" node="1YCbHn1AKJT" resolve="A" />
+                                      </node>
+                                    </node>
+                                  </node>
+                                </node>
+                              </node>
+                            </node>
+                          </node>
+                        </node>
+                      </node>
+                    </node>
+                  </node>
+                </node>
+              </node>
+            </node>
+          </node>
+          <node concept="3I6s7M" id="1YCbHn1AKBE" role="3I6sU7">
+            <node concept="3XxkQB" id="1YCbHn1AKBA" role="3I6s78">
+              <node concept="aYllk" id="1YCbHn1AKBB" role="3XxmmS">
+                <node concept="3A2sRY" id="1YCbHn1AKBQ" role="aYrYs">
+                  <ref role="3A2yKK" node="1YCbHn1AJ$P" resolve="fix" />
+                </node>
+              </node>
+              <node concept="a7P8L" id="1YCbHn1AQr7" role="3Xxm5W">
+                <ref role="a7OzE" node="1YCbHn1AQkt" resolve="F" />
+              </node>
+            </node>
+          </node>
+        </node>
+        <node concept="3NuqgR" id="1YCbHn1AKJS" role="3Nuqhd">
+          <node concept="aZer4" id="1YCbHn1AQkt" role="3XD1gS">
+            <property role="TrG5h" value="F" />
+          </node>
+          <node concept="aZer4" id="1YCbHn1AKJT" role="3XD1gS">
+            <property role="TrG5h" value="A" />
+          </node>
+        </node>
+      </node>
+    </node>
   </node>
   <node concept="3AqmoV" id="44a9n8ErYcS">
     <property role="TrG5h" value="constraints" />
diff --git a/samples/lambdacalc/solutions/sample.demo/models/sample/demo/fooblah.mps b/samples/lambdacalc/solutions/sample.demo/models/sample/demo/fooblah.mps
index b81448e2..65db2bc1 100644
--- a/samples/lambdacalc/solutions/sample.demo/models/sample/demo/fooblah.mps
+++ b/samples/lambdacalc/solutions/sample.demo/models/sample/demo/fooblah.mps
@@ -12,6 +12,7 @@
       </concept>
     </language>
     <language id="af858d84-85f2-42f4-a854-0b3c6b5cd482" name="sample.fooblin">
+      <concept id="1784752312119229448" name="sample.fooblin.structure.Fix" flags="ng" index="2facFd" />
       <concept id="8747055848970356251" name="sample.fooblin.structure.VarRef" flags="ng" index="t0$VC">
         <reference id="8747055848970356252" name="def" index="t0$VJ" />
       </concept>
@@ -216,6 +217,82 @@
         </node>
       </node>
     </node>
+    <node concept="1DVJbV" id="1LGA6BuFeVl" role="1DVIru">
+      <node concept="1DVIrG" id="1LGA6BuFeVn" role="j9CMd">
+        <node concept="1DVIoH" id="1LGA6BuFeVp" role="1DVIrJ">
+          <property role="TrG5h" value="suc" />
+        </node>
+        <node concept="1DVIrU" id="1LGA6BuFeWB" role="1DVIrD">
+          <node concept="1DVIrB" id="1LGA6BuFeWC" role="1DVIr_">
+            <node concept="1DVIoH" id="1LGA6BuFeWD" role="1DVIrA">
+              <property role="TrG5h" value="n" />
+            </node>
+          </node>
+          <node concept="1DVIrU" id="1LGA6BuFeWH" role="1DVIrw">
+            <node concept="1DVIrB" id="1LGA6BuFeWI" role="1DVIr_">
+              <node concept="1DVIoH" id="1LGA6BuFeWJ" role="1DVIrA">
+                <property role="TrG5h" value="f" />
+              </node>
+            </node>
+            <node concept="1DVIrU" id="1LGA6BuFeWN" role="1DVIrw">
+              <node concept="1DVIrB" id="1LGA6BuFeWO" role="1DVIr_">
+                <node concept="1DVIoH" id="1LGA6BuFeWP" role="1DVIrA">
+                  <property role="TrG5h" value="x" />
+                </node>
+              </node>
+              <node concept="1DVIo5" id="1LGA6BuFeWY" role="1DVIrw">
+                <node concept="t0$VC" id="1LGA6BuFeWT" role="1DVIo4">
+                  <ref role="t0$VJ" node="1LGA6BuFeWJ" resolve="f" />
+                </node>
+                <node concept="1DVIo5" id="1LGA6BuFeXg" role="1DVIo8">
+                  <node concept="1DVIo5" id="1LGA6BuFeXz" role="1DVIo4">
+                    <node concept="t0$VC" id="1LGA6BuFeWX" role="1DVIo4">
+                      <ref role="t0$VJ" node="1LGA6BuFeWD" resolve="n" />
+                    </node>
+                    <node concept="t0$VC" id="1LGA6BuFeXy" role="1DVIo8">
+                      <ref role="t0$VJ" node="1LGA6BuFeWJ" resolve="f" />
+                    </node>
+                  </node>
+                  <node concept="t0$VC" id="1LGA6BuFeXt" role="1DVIo8">
+                    <ref role="t0$VJ" node="1LGA6BuFeWP" resolve="x" />
+                  </node>
+                </node>
+              </node>
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
+    <node concept="1DVJbV" id="1LGA6BuFeZ9" role="1DVIru">
+      <node concept="1DVIrG" id="1LGA6BuFeZb" role="j9CMd">
+        <node concept="1DVIoH" id="1LGA6BuFeZd" role="1DVIrJ">
+          <property role="TrG5h" value="zero_plus_one" />
+        </node>
+        <node concept="1DVIo5" id="1LGA6BuFf0O" role="1DVIrD">
+          <node concept="t0$VC" id="1LGA6BuFf0I" role="1DVIo4">
+            <ref role="t0$VJ" node="1LGA6BuFeVp" resolve="suc" />
+          </node>
+          <node concept="t0$VC" id="1LGA6BuFf0N" role="1DVIo8">
+            <ref role="t0$VJ" node="2jleysRWYyY" resolve="zero" />
+          </node>
+        </node>
+      </node>
+    </node>
+    <node concept="1DVJbV" id="1LGA6BuFfaA" role="1DVIru">
+      <node concept="1DVIrG" id="1LGA6BuFfaB" role="j9CMd">
+        <node concept="1DVIoH" id="1LGA6BuFfaC" role="1DVIrJ">
+          <property role="TrG5h" value="one_plus_one" />
+        </node>
+        <node concept="1DVIo5" id="1LGA6BuFfaD" role="1DVIrD">
+          <node concept="t0$VC" id="1LGA6BuFfaE" role="1DVIo4">
+            <ref role="t0$VJ" node="1LGA6BuFeVp" resolve="suc" />
+          </node>
+          <node concept="t0$VC" id="1LGA6BuFfch" role="1DVIo8">
+            <ref role="t0$VJ" node="2jleysRWYzk" resolve="one" />
+          </node>
+        </node>
+      </node>
+    </node>
   </node>
   <node concept="1DVIrt" id="1PL$JmLA85j">
     <property role="TrG5h" value="Y_combinator" />
@@ -586,7 +663,7 @@
     <node concept="1DVJbV" id="2jleysRX4cu" role="1DVIru">
       <node concept="1DVIrG" id="2jleysRX4cw" role="j9CMd">
         <node concept="1DVIoH" id="2jleysRX4cS" role="1DVIrJ">
-          <property role="TrG5h" value="fix" />
+          <property role="TrG5h" value="fix_bad" />
         </node>
         <node concept="1DVIrU" id="2jleysRX4cZ" role="1DVIrD">
           <node concept="1DVIrB" id="2jleysRX4d7" role="1DVIr_">
@@ -615,19 +692,76 @@
         </node>
       </node>
     </node>
-    <node concept="1DVJbV" id="3TFdEPZeElu" role="1DVIru">
-      <node concept="1DVIrG" id="3TFdEPZeElw" role="j9CMd">
-        <node concept="1DVIoH" id="3TFdEPZeEly" role="1DVIrJ">
-          <property role="TrG5h" value="asd" />
+    <node concept="1DVJbV" id="1YCbHn1AbJG" role="1DVIru">
+      <node concept="1DVIrG" id="1YCbHn1AbJI" role="j9CMd">
+        <node concept="1DVIoH" id="1YCbHn1AbJK" role="1DVIrJ">
+          <property role="TrG5h" value="g" />
         </node>
-        <node concept="1DVIrU" id="3TFdEPZeS$J" role="1DVIrD">
-          <node concept="1DVIrB" id="3TFdEPZeS$K" role="1DVIr_">
-            <node concept="1DVIoH" id="3TFdEPZeS$L" role="1DVIrA">
-              <property role="TrG5h" value="x" />
+        <node concept="1DVIrU" id="1YCbHn1AbKi" role="1DVIrD">
+          <node concept="1DVIrB" id="1YCbHn1AbKj" role="1DVIr_">
+            <node concept="1DVIoH" id="1YCbHn1AbKk" role="1DVIrA">
+              <property role="TrG5h" value="rec" />
             </node>
           </node>
-          <node concept="t0$VC" id="3TFdEPZeS$P" role="1DVIrw">
-            <ref role="t0$VJ" node="3TFdEPZeS$L" resolve="x" />
+          <node concept="1DVIrU" id="1YCbHn1AbKl" role="1DVIrw">
+            <node concept="1DVIrB" id="1YCbHn1AbKm" role="1DVIr_">
+              <node concept="1DVIoH" id="1YCbHn1AbKn" role="1DVIrA">
+                <property role="TrG5h" value="n" />
+              </node>
+            </node>
+            <node concept="1DVIo5" id="1YCbHn1AbKo" role="1DVIrw">
+              <node concept="t0$VC" id="1YCbHn1AbKp" role="1DVIo4">
+                <ref role="t0$VJ" node="1YCbHn1AbKk" resolve="rec" />
+              </node>
+              <node concept="t0$VC" id="1YCbHn1AbKq" role="1DVIo8">
+                <ref role="t0$VJ" node="1YCbHn1AbKn" resolve="n" />
+              </node>
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
+    <node concept="1DVJbV" id="1YCbHn1AJbt" role="1DVIru">
+      <node concept="1DVIrG" id="1YCbHn1AJbv" role="j9CMd">
+        <node concept="1DVIoH" id="1YCbHn1AJbx" role="1DVIrJ">
+          <property role="TrG5h" value="f" />
+        </node>
+        <node concept="1DVIo5" id="1YCbHn1AJc8" role="1DVIrD">
+          <node concept="2facFd" id="1YCbHn1AJc2" role="1DVIo4" />
+          <node concept="t0$VC" id="1YCbHn1AJc7" role="1DVIo8">
+            <ref role="t0$VJ" node="1YCbHn1AbJK" resolve="g" />
+          </node>
+        </node>
+      </node>
+    </node>
+    <node concept="1DVJbV" id="1YCbHn1AVG3" role="1DVIru">
+      <node concept="1DVIrG" id="1YCbHn1AVG5" role="j9CMd">
+        <node concept="1DVIoH" id="1YCbHn1AVG7" role="1DVIrJ">
+          <property role="TrG5h" value="f2" />
+        </node>
+        <node concept="1DVIo5" id="1YCbHn1AVGO" role="1DVIrD">
+          <node concept="2facFd" id="1YCbHn1AVGI" role="1DVIo4" />
+          <node concept="1DVIrU" id="1YCbHn1AVH1" role="1DVIo8">
+            <node concept="1DVIrB" id="1YCbHn1AVH2" role="1DVIr_">
+              <node concept="1DVIoH" id="1YCbHn1AVH3" role="1DVIrA">
+                <property role="TrG5h" value="rec" />
+              </node>
+            </node>
+            <node concept="1DVIrU" id="1YCbHn1AVH4" role="1DVIrw">
+              <node concept="1DVIrB" id="1YCbHn1AVH5" role="1DVIr_">
+                <node concept="1DVIoH" id="1YCbHn1AVH6" role="1DVIrA">
+                  <property role="TrG5h" value="n" />
+                </node>
+              </node>
+              <node concept="1DVIo5" id="1YCbHn1AVH7" role="1DVIrw">
+                <node concept="t0$VC" id="1YCbHn1AVH8" role="1DVIo4">
+                  <ref role="t0$VJ" node="1YCbHn1AVH3" resolve="rec" />
+                </node>
+                <node concept="t0$VC" id="1YCbHn1AVH9" role="1DVIo8">
+                  <ref role="t0$VJ" node="1YCbHn1AVH6" resolve="n" />
+                </node>
+              </node>
+            </node>
           </node>
         </node>
       </node>