From a2012219b78f12966f80f3ed03bb9ffa7107108d Mon Sep 17 00:00:00 2001
From: "grigorii.kirgizov" <grigorii.kirgizov@jetbrains.com>
Date: Mon, 28 Jan 2019 13:32:32 +0300
Subject: [PATCH] lc: Fix spurious typeConstraints reactivation on forall gen.
 Fix recursive case in instanceCheck.

As a consequence, there's a simplification of produceTypeConstraints rules.
Also add comments and fix some test cases: some of them are actually typeable.
Now tests are correct (checked against Haskell's typechecker) and all pass.
---
 .../samples.lambdacalc/models/types.mps       | 827 ++++++------------
 .../models/samples.lambdacalc.demo.mps        | 589 ++++++++++---
 .../models/samples.lambdacalc.demo@tests.mps  |  63 +-
 3 files changed, 743 insertions(+), 736 deletions(-)

diff --git a/samples/lambdacalc/languages/samples.lambdacalc/models/types.mps b/samples/lambdacalc/languages/samples.lambdacalc/models/types.mps
index 4947d607..dc4b8f64 100644
--- a/samples/lambdacalc/languages/samples.lambdacalc/models/types.mps
+++ b/samples/lambdacalc/languages/samples.lambdacalc/models/types.mps
@@ -2040,118 +2040,122 @@
             <property role="3SKdUp" value="recursive binding..." />
           </node>
         </node>
-        <node concept="1nLNNL" id="38y1JL54_lj" role="3cqZAp">
-          <node concept="1nLNMm" id="38y1JL54_ll" role="1nLNNK">
-            <node concept="3Aq9E8" id="38y1JL54_ot" role="1nLNMd">
-              <node concept="3I6sU6" id="38y1JL54_ou" role="3Ip0Jz">
-                <node concept="3IrJb3" id="38y1JL54_$7" role="3I6sU7">
-                  <node concept="3clFbS" id="38y1JL54_$8" role="3IrJb0">
-                    <node concept="1X3_iC" id="38y1JL55$tG" role="lGtFl">
-                      <property role="3V$3am" value="statement" />
-                      <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
-                      <node concept="3Aqczg" id="38y1JL54_$9" role="8Wnug">
-                        <node concept="3A8Hvi" id="38y1JL54_y0" role="3Aqpz8">
-                          <node concept="ns1u0" id="38y1JL54_yu" role="3A8w4Q">
-                            <ref role="ns1xF" node="JqEP$8smGC" resolve="Pair" />
-                            <node concept="nsMwS" id="38y1JL54_yw" role="ns1xD">
-                              <ref role="nsMwP" node="JqEP$8smGP" resolve="fst" />
-                              <node concept="1nq8_$" id="38y1JL54_yA" role="nsMwV">
-                                <node concept="a7P8L" id="38y1JL54_zf" role="1nq8_t">
-                                  <ref role="a7OzE" node="3vXKzDNXAC$" resolve="T" />
+        <node concept="1X3_iC" id="47xL5G3dZO$" role="lGtFl">
+          <property role="3V$3am" value="statement" />
+          <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
+          <node concept="1nLNNL" id="38y1JL54_lj" role="8Wnug">
+            <node concept="1nLNMm" id="38y1JL54_ll" role="1nLNNK">
+              <node concept="3Aq9E8" id="38y1JL54_ot" role="1nLNMd">
+                <node concept="3I6sU6" id="38y1JL54_ou" role="3Ip0Jz">
+                  <node concept="3IrJb3" id="38y1JL54_$7" role="3I6sU7">
+                    <node concept="3clFbS" id="38y1JL54_$8" role="3IrJb0">
+                      <node concept="1X3_iC" id="38y1JL55$tG" role="lGtFl">
+                        <property role="3V$3am" value="statement" />
+                        <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
+                        <node concept="3Aqczg" id="38y1JL54_$9" role="8Wnug">
+                          <node concept="3A8Hvi" id="38y1JL54_y0" role="3Aqpz8">
+                            <node concept="ns1u0" id="38y1JL54_yu" role="3A8w4Q">
+                              <ref role="ns1xF" node="JqEP$8smGC" resolve="Pair" />
+                              <node concept="nsMwS" id="38y1JL54_yw" role="ns1xD">
+                                <ref role="nsMwP" node="JqEP$8smGP" resolve="fst" />
+                                <node concept="1nq8_$" id="38y1JL54_yA" role="nsMwV">
+                                  <node concept="a7P8L" id="38y1JL54_zf" role="1nq8_t">
+                                    <ref role="a7OzE" node="3vXKzDNXAC$" resolve="T" />
+                                  </node>
+                                </node>
+                              </node>
+                              <node concept="nsMwS" id="38y1JL54_yH" role="ns1xD">
+                                <ref role="nsMwP" node="JqEP$8smGY" resolve="snd" />
+                                <node concept="1nq8_$" id="38y1JL54_yQ" role="nsMwV">
+                                  <node concept="a7P8L" id="38y1JL54_yX" role="1nq8_t">
+                                    <ref role="a7OzE" node="3vXKzDNXABC" resolve="S" />
+                                  </node>
                                 </node>
                               </node>
                             </node>
-                            <node concept="nsMwS" id="38y1JL54_yH" role="ns1xD">
-                              <ref role="nsMwP" node="JqEP$8smGY" resolve="snd" />
-                              <node concept="1nq8_$" id="38y1JL54_yQ" role="nsMwV">
-                                <node concept="a7P8L" id="38y1JL54_yX" role="1nq8_t">
-                                  <ref role="a7OzE" node="3vXKzDNXABC" resolve="S" />
-                                </node>
-                              </node>
-                            </node>
-                          </node>
-                          <node concept="a7P8L" id="38y1JL54_$2" role="3A8wtg">
-                            <ref role="a7OzE" node="3vXKzDNXAC$" resolve="T" />
-                          </node>
-                        </node>
-                      </node>
-                    </node>
-                    <node concept="3clFbH" id="38y1JL56C$3" role="3cqZAp" />
-                    <node concept="3Aqczg" id="38y1JL54_$a" role="3cqZAp">
-                      <node concept="3A8Hvi" id="38y1JL54_ox" role="3Aqpz8">
-                        <node concept="a7P8L" id="38y1JL54_oI" role="3A8wtg">
-                          <ref role="a7OzE" node="1IKbs5XE3w$" resolve="U1" />
-                        </node>
-                        <node concept="ns1u0" id="38y1JL54_pk" role="3A8w4Q">
-                          <ref role="ns1xF" node="JqEP$8smGC" resolve="Pair" />
-                          <node concept="nsMwS" id="38y1JL54_pm" role="ns1xD">
-                            <ref role="nsMwP" node="JqEP$8smGP" resolve="fst" />
-                            <node concept="1nq8_$" id="38y1JL54_ps" role="nsMwV">
-                              <node concept="a7P8L" id="38y1JL56CEP" role="1nq8_t">
-                                <ref role="a7OzE" node="1IKbs5XDAKq" resolve="A" />
-                              </node>
-                            </node>
-                          </node>
-                          <node concept="nsMwS" id="38y1JL54_pz" role="ns1xD">
-                            <ref role="nsMwP" node="JqEP$8smGY" resolve="snd" />
-                            <node concept="1nq8_$" id="38y1JL54_pU" role="nsMwV">
-                              <node concept="a7P8L" id="38y1JL54_pS" role="1nq8_t">
-                                <ref role="a7OzE" node="1IKbs5XDAKz" resolve="B" />
-                              </node>
+                            <node concept="a7P8L" id="38y1JL54_$2" role="3A8wtg">
+                              <ref role="a7OzE" node="3vXKzDNXAC$" resolve="T" />
                             </node>
                           </node>
                         </node>
                       </node>
-                    </node>
-                    <node concept="3clFbH" id="38y1JL56CB3" role="3cqZAp" />
-                    <node concept="3SKdUt" id="38y1JL56Czs" role="3cqZAp">
-                      <node concept="3SKdUq" id="38y1JL56Czu" role="3SKWNk">
-                        <property role="3SKdUp" value="fails, occurs check" />
-                      </node>
-                    </node>
-                    <node concept="1X3_iC" id="38y1JL56Cxn" role="lGtFl">
-                      <property role="3V$3am" value="statement" />
-                      <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
-                      <node concept="3Aqczg" id="38y1JL56CwF" role="8Wnug">
-                        <node concept="3A8Hvi" id="38y1JL56Cw_" role="3Aqpz8">
-                          <node concept="a7P8L" id="38y1JL56Cxd" role="3A8wtg">
-                            <ref role="a7OzE" node="1IKbs5XDAKq" resolve="A" />
-                          </node>
-                          <node concept="a7P8L" id="38y1JL56Cxi" role="3A8w4Q">
+                      <node concept="3clFbH" id="38y1JL56C$3" role="3cqZAp" />
+                      <node concept="3Aqczg" id="38y1JL54_$a" role="3cqZAp">
+                        <node concept="3A8Hvi" id="38y1JL54_ox" role="3Aqpz8">
+                          <node concept="a7P8L" id="38y1JL54_oI" role="3A8wtg">
                             <ref role="a7OzE" node="1IKbs5XE3w$" resolve="U1" />
                           </node>
+                          <node concept="ns1u0" id="38y1JL54_pk" role="3A8w4Q">
+                            <ref role="ns1xF" node="JqEP$8smGC" resolve="Pair" />
+                            <node concept="nsMwS" id="38y1JL54_pm" role="ns1xD">
+                              <ref role="nsMwP" node="JqEP$8smGP" resolve="fst" />
+                              <node concept="1nq8_$" id="38y1JL54_ps" role="nsMwV">
+                                <node concept="a7P8L" id="38y1JL56CEP" role="1nq8_t">
+                                  <ref role="a7OzE" node="1IKbs5XDAKq" resolve="A" />
+                                </node>
+                              </node>
+                            </node>
+                            <node concept="nsMwS" id="38y1JL54_pz" role="ns1xD">
+                              <ref role="nsMwP" node="JqEP$8smGY" resolve="snd" />
+                              <node concept="1nq8_$" id="38y1JL54_pU" role="nsMwV">
+                                <node concept="a7P8L" id="38y1JL54_pS" role="1nq8_t">
+                                  <ref role="a7OzE" node="1IKbs5XDAKz" resolve="B" />
+                                </node>
+                              </node>
+                            </node>
+                          </node>
                         </node>
                       </node>
-                    </node>
-                    <node concept="3clFbH" id="38y1JL56CBE" role="3cqZAp" />
-                    <node concept="3Aqczg" id="38y1JL56CM2" role="3cqZAp">
-                      <node concept="3A8Hvi" id="38y1JL56CM3" role="3Aqpz8">
-                        <node concept="a7P8L" id="38y1JL56CM4" role="3A8wtg">
-                          <ref role="a7OzE" node="38y1JL56CG0" resolve="A1" />
-                        </node>
-                        <node concept="a7P8L" id="38y1JL56CM5" role="3A8w4Q">
-                          <ref role="a7OzE" node="1IKbs5XDAKq" resolve="A" />
+                      <node concept="3clFbH" id="38y1JL56CB3" role="3cqZAp" />
+                      <node concept="3SKdUt" id="38y1JL56Czs" role="3cqZAp">
+                        <node concept="3SKdUq" id="38y1JL56Czu" role="3SKWNk">
+                          <property role="3SKdUp" value="fails, occurs check" />
                         </node>
                       </node>
-                    </node>
-                    <node concept="3Aqczg" id="38y1JL56CQ1" role="3cqZAp">
-                      <node concept="3A8Hvi" id="38y1JL56CPV" role="3Aqpz8">
-                        <node concept="a7P8L" id="38y1JL56CR1" role="3A8wtg">
-                          <ref role="a7OzE" node="38y1JL56CG0" resolve="A1" />
+                      <node concept="1X3_iC" id="38y1JL56Cxn" role="lGtFl">
+                        <property role="3V$3am" value="statement" />
+                        <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
+                        <node concept="3Aqczg" id="38y1JL56CwF" role="8Wnug">
+                          <node concept="3A8Hvi" id="38y1JL56Cw_" role="3Aqpz8">
+                            <node concept="a7P8L" id="38y1JL56Cxd" role="3A8wtg">
+                              <ref role="a7OzE" node="1IKbs5XDAKq" resolve="A" />
+                            </node>
+                            <node concept="a7P8L" id="38y1JL56Cxi" role="3A8w4Q">
+                              <ref role="a7OzE" node="1IKbs5XE3w$" resolve="U1" />
+                            </node>
+                          </node>
                         </node>
-                        <node concept="a7P8L" id="38y1JL58feM" role="3A8w4Q">
-                          <ref role="a7OzE" node="1IKbs5XE3w$" resolve="U1" />
+                      </node>
+                      <node concept="3clFbH" id="38y1JL56CBE" role="3cqZAp" />
+                      <node concept="3Aqczg" id="38y1JL56CM2" role="3cqZAp">
+                        <node concept="3A8Hvi" id="38y1JL56CM3" role="3Aqpz8">
+                          <node concept="a7P8L" id="38y1JL56CM4" role="3A8wtg">
+                            <ref role="a7OzE" node="38y1JL56CG0" resolve="A1" />
+                          </node>
+                          <node concept="a7P8L" id="38y1JL56CM5" role="3A8w4Q">
+                            <ref role="a7OzE" node="1IKbs5XDAKq" resolve="A" />
+                          </node>
+                        </node>
+                      </node>
+                      <node concept="3Aqczg" id="38y1JL56CQ1" role="3cqZAp">
+                        <node concept="3A8Hvi" id="38y1JL56CPV" role="3Aqpz8">
+                          <node concept="a7P8L" id="38y1JL56CR1" role="3A8wtg">
+                            <ref role="a7OzE" node="38y1JL56CG0" resolve="A1" />
+                          </node>
+                          <node concept="a7P8L" id="38y1JL58feM" role="3A8w4Q">
+                            <ref role="a7OzE" node="1IKbs5XE3w$" resolve="U1" />
+                          </node>
                         </node>
                       </node>
                     </node>
                   </node>
                 </node>
               </node>
-            </node>
-            <node concept="0eUR_" id="38y1JL56CFX" role="0UC6o">
-              <node concept="3NuqgR" id="38y1JL56CFZ" role="0eVf_">
-                <node concept="aZer4" id="38y1JL56CG0" role="3XD1gS">
-                  <property role="TrG5h" value="A1" />
+              <node concept="0eUR_" id="38y1JL56CFX" role="0UC6o">
+                <node concept="3NuqgR" id="38y1JL56CFZ" role="0eVf_">
+                  <node concept="aZer4" id="38y1JL56CG0" role="3XD1gS">
+                    <property role="TrG5h" value="A1" />
+                  </node>
                 </node>
               </node>
             </node>
@@ -6559,7 +6563,7 @@
       </node>
     </node>
     <node concept="3AqmO8" id="48ZGLP7pk5w" role="8PkJo">
-      <property role="TrG5h" value="freeTypeVars" />
+      <property role="TrG5h" value="genTypeVars" />
       <node concept="1zAUYm" id="48ZGLP7pkpg" role="1zAUyy">
         <property role="TrG5h" value="typeVars" />
       </node>
@@ -6583,7 +6587,7 @@
       </node>
     </node>
     <node concept="1nLNMY" id="48ZGLP7ppHO" role="1nK1Vg">
-      <property role="TrG5h" value="freeTypeVars_baseCase" />
+      <property role="TrG5h" value="genTypeVars_baseCase" />
       <node concept="3clFbS" id="48ZGLP7ppHP" role="1nLNMH">
         <node concept="1nLNNL" id="48ZGLP7ppM2" role="3cqZAp">
           <node concept="1nLNMm" id="48ZGLP7ppM3" role="1nLNNK">
@@ -6598,7 +6602,7 @@
               <node concept="3I6sU6" id="48ZGLP7ppMn" role="3Ip0Jz">
                 <node concept="3I6s7M" id="48ZGLP7ppMr" role="3I6sU7">
                   <node concept="3Aqt3T" id="48ZGLP7ppMq" role="3I6s78">
-                    <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="freeTypeVars" />
+                    <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="genTypeVars" />
                     <node concept="ns1u0" id="48ZGLP7ppMu" role="3AunhB">
                       <ref role="ns1xF" node="48ZGLP7pl6N" resolve="Nil" />
                     </node>
@@ -6628,7 +6632,7 @@
       </node>
     </node>
     <node concept="1nLNMY" id="2O9ahh6Lpuj" role="1nK1Vg">
-      <property role="TrG5h" value="freeTypeVars_isFree" />
+      <property role="TrG5h" value="genTypeVars_isFree" />
       <node concept="3clFbS" id="2O9ahh6Lpuk" role="1nLNMH">
         <node concept="1nLNNL" id="2O9ahh6Lpu_" role="3cqZAp">
           <node concept="1nLNMm" id="2O9ahh6LpuA" role="1nLNNK">
@@ -6636,7 +6640,7 @@
               <node concept="3I6sU6" id="2O9ahh6LpuC" role="3Ip0Jz">
                 <node concept="3I6s7M" id="2O9ahh6LpuD" role="3I6sU7">
                   <node concept="3Aqt3T" id="2O9ahh6LpuE" role="3I6s78">
-                    <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="freeTypeVars" />
+                    <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="genTypeVars" />
                     <node concept="1HFMs5" id="2O9ahh6LpuF" role="3AunhB">
                       <node concept="a7P8L" id="2O9ahh6LpuG" role="1uarlU">
                         <ref role="a7OzE" node="2O9ahh6LpuT" resolve="TVs" />
@@ -6705,6 +6709,37 @@
               <node concept="3I6sU6" id="2O9ahh6Lpv5" role="3Ip0Jz">
                 <node concept="3IrJb3" id="2O9ahh6Sq99" role="3I6sU7">
                   <node concept="3clFbS" id="2O9ahh6Sq9a" role="3IrJb0">
+                    <node concept="3SKdUt" id="47xL5G3eTDw" role="3cqZAp">
+                      <node concept="3SKdUq" id="47xL5G3eTDy" role="3SKWNk">
+                        <property role="3SKdUp" value="Need to produce type Constraints before changing TVRef" />
+                      </node>
+                    </node>
+                    <node concept="3SKdUt" id="47xL5G3eTE2" role="3cqZAp">
+                      <node concept="3SKdUq" id="47xL5G3eTE3" role="3SKWNk">
+                        <property role="3SKdUp" value=" to avoid spurious activation of typeConstraints_discharge" />
+                      </node>
+                    </node>
+                    <node concept="3Aqczg" id="47xL5G3eToM" role="3cqZAp">
+                      <node concept="3Aqt3T" id="47xL5G3eTq1" role="3Aqpz8">
+                        <ref role="3AqCNq" node="47xL5G3eTpn" resolve="produceTypeConstraints" />
+                        <node concept="a7P8L" id="47xL5G3eTq6" role="3AunhB">
+                          <ref role="a7OzE" node="2O9ahh6LpuV" resolve="TVRef" />
+                        </node>
+                        <node concept="a7P8L" id="47xL5G3eTqc" role="3AunhB">
+                          <ref role="a7OzE" node="2O9ahh6LpuU" resolve="Free" />
+                        </node>
+                      </node>
+                    </node>
+                    <node concept="3SKdUt" id="47xL5G3eSVb" role="3cqZAp">
+                      <node concept="3SKdUq" id="47xL5G3eSVd" role="3SKWNk">
+                        <property role="3SKdUp" value="We generalize over this type var (TVRef)," />
+                      </node>
+                    </node>
+                    <node concept="3SKdUt" id="47xL5G3eSV_" role="3cqZAp">
+                      <node concept="3SKdUq" id="47xL5G3eSVA" role="3SKWNk">
+                        <property role="3SKdUp" value=" so mark its occurences in the type (that we generalize) as references" />
+                      </node>
+                    </node>
                     <node concept="3Aqczg" id="2O9ahh6Sq9b" role="3cqZAp">
                       <node concept="3A8Hvi" id="2O9ahh6Lpvq" role="3Aqpz8">
                         <node concept="a7P8L" id="2O9ahh6Lpvr" role="3A8wtg">
@@ -6723,15 +6758,9 @@
                         </node>
                       </node>
                     </node>
-                    <node concept="3Aqczg" id="2O9ahh6Sq9c" role="3cqZAp">
-                      <node concept="3Aqt3T" id="2O9ahh6LpvA" role="3Aqpz8">
-                        <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="freeTypeVars" />
-                        <node concept="a7P8L" id="2O9ahh6LpvB" role="3AunhB">
-                          <ref role="a7OzE" node="2O9ahh6LpuW" resolve="TVsTail" />
-                        </node>
-                        <node concept="a7P8L" id="2O9ahh6LpvC" role="3AunhB">
-                          <ref role="a7OzE" node="2O9ahh6Lpv0" resolve="FreeTail" />
-                        </node>
+                    <node concept="3SKdUt" id="47xL5G3gguU" role="3cqZAp">
+                      <node concept="3SKdUq" id="47xL5G3gguW" role="3SKWNk">
+                        <property role="3SKdUp" value="Collect produced type var definitions" />
                       </node>
                     </node>
                     <node concept="3Aqczg" id="2O9ahh6Sq9d" role="3cqZAp">
@@ -6760,6 +6789,22 @@
                         </node>
                       </node>
                     </node>
+                    <node concept="3SKdUt" id="47xL5G3ggxH" role="3cqZAp">
+                      <node concept="3SKdUq" id="47xL5G3ggxJ" role="3SKWNk">
+                        <property role="3SKdUp" value="Process type vars left" />
+                      </node>
+                    </node>
+                    <node concept="3Aqczg" id="2O9ahh6Sq9c" role="3cqZAp">
+                      <node concept="3Aqt3T" id="2O9ahh6LpvA" role="3Aqpz8">
+                        <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="genTypeVars" />
+                        <node concept="a7P8L" id="2O9ahh6LpvB" role="3AunhB">
+                          <ref role="a7OzE" node="2O9ahh6LpuW" resolve="TVsTail" />
+                        </node>
+                        <node concept="a7P8L" id="2O9ahh6LpvC" role="3AunhB">
+                          <ref role="a7OzE" node="2O9ahh6Lpv0" resolve="FreeTail" />
+                        </node>
+                      </node>
+                    </node>
                   </node>
                 </node>
               </node>
@@ -6780,7 +6825,7 @@
       </node>
     </node>
     <node concept="1nLNMY" id="48ZGLP7pqn$" role="1nK1Vg">
-      <property role="TrG5h" value="freeTypeVars_nonFree" />
+      <property role="TrG5h" value="genTypeVars_nonFree" />
       <node concept="3clFbS" id="48ZGLP7pqn_" role="1nLNMH">
         <node concept="1nLNNL" id="48ZGLP7pqnA" role="3cqZAp">
           <node concept="1nLNMm" id="48ZGLP7pqnB" role="1nLNNK">
@@ -6788,7 +6833,7 @@
               <node concept="3I6sU6" id="48ZGLP7pqnD" role="3Ip0Jz">
                 <node concept="3I6s7M" id="48ZGLP7pqnE" role="3I6sU7">
                   <node concept="3Aqt3T" id="48ZGLP7pqnF" role="3I6s78">
-                    <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="freeTypeVars" />
+                    <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="genTypeVars" />
                     <node concept="1HFMs5" id="48ZGLP7pqnG" role="3AunhB">
                       <node concept="a7P8L" id="48ZGLP7pqnH" role="1uarlU">
                         <ref role="a7OzE" node="48ZGLP7pqnS" resolve="TVs" />
@@ -6845,7 +6890,7 @@
               <node concept="3I6sU6" id="48ZGLP7pqnZ" role="3Ip0Jz">
                 <node concept="3I6s7M" id="48ZGLP7pqo0" role="3I6sU7">
                   <node concept="3Aqt3T" id="48ZGLP7pqo1" role="3I6s78">
-                    <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="freeTypeVars" />
+                    <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="genTypeVars" />
                     <node concept="a7P8L" id="48ZGLP7pqo2" role="3AunhB">
                       <ref role="a7OzE" node="48ZGLP7pqnU" resolve="Tail" />
                     </node>
@@ -6905,7 +6950,7 @@
                   <node concept="3clFbS" id="47tET_W9xOj" role="3IrJb0">
                     <node concept="3Aqczg" id="47tET_W9xOk" role="3cqZAp">
                       <node concept="3Aqt3T" id="48ZGLP7MMNX" role="3Aqpz8">
-                        <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="freeTypeVars" />
+                        <ref role="3AqCNq" node="48ZGLP7pk5w" resolve="genTypeVars" />
                         <node concept="a7P8L" id="48ZGLP7MMO5" role="3AunhB">
                           <ref role="a7OzE" node="48ZGLP7MMM7" resolve="TVs" />
                         </node>
@@ -6914,14 +6959,6 @@
                         </node>
                       </node>
                     </node>
-                    <node concept="3Aqczg" id="47tET_W9xOl" role="3cqZAp">
-                      <node concept="3Aqt3T" id="47tET_W6G_D" role="3Aqpz8">
-                        <ref role="3AqCNq" node="47tET_W6Fxn" resolve="produceTypeConstraints" />
-                        <node concept="a7P8L" id="47tET_W6G_T" role="3AunhB">
-                          <ref role="a7OzE" node="48ZGLP7MMMn" resolve="FreeTVs" />
-                        </node>
-                      </node>
-                    </node>
                     <node concept="3Aqczg" id="47tET_W9xOm" role="3cqZAp">
                       <node concept="3Aqt3T" id="48ZGLP7MMOs" role="3Aqpz8">
                         <ref role="3AqCNq" node="48ZGLP7pkwP" resolve="genTV" />
@@ -11619,16 +11656,13 @@
         <property role="TrG5h" value="set" />
       </node>
     </node>
-    <node concept="3AqmO8" id="47tET_W6Fxn" role="8PkJo">
+    <node concept="3AqmO8" id="47xL5G3eTpn" role="8PkJo">
       <property role="TrG5h" value="produceTypeConstraints" />
-      <node concept="1zAUYm" id="47tET_W6FC6" role="1zAUyy">
-        <property role="TrG5h" value="typeVars" />
+      <node concept="1zAUYm" id="47xL5G3eTpo" role="1zAUyy">
+        <property role="TrG5h" value="typeVarOrigin" />
       </node>
-    </node>
-    <node concept="3AqmO8" id="47tET_XcN9h" role="8PkJo">
-      <property role="TrG5h" value="produceTypeConstraint" />
-      <node concept="1zAUYm" id="47tET_XcN9O" role="1zAUyy">
-        <property role="TrG5h" value="typeVar" />
+      <node concept="1zAUYm" id="47xL5G3eTpY" role="1zAUyy">
+        <property role="TrG5h" value="typeVarDef" />
       </node>
     </node>
     <node concept="3AqmO8" id="47tET_WlK9C" role="8PkJo">
@@ -11801,7 +11835,6 @@
         <node concept="1nLNNL" id="47tET_WGoXa" role="3cqZAp">
           <node concept="1nLNMm" id="47tET_WGoXb" role="1nLNNK">
             <node concept="3Aq93q" id="47tET_WGoXc" role="1nLNMb">
-              <property role="3ArMco" value="true" />
               <node concept="3I6sU6" id="47tET_WGoXd" role="3Ip0Jz">
                 <node concept="3I6s7M" id="47tET_WGoXe" role="3I6sU7">
                   <node concept="3Aqt3T" id="47tET_WGoXf" role="3I6s78">
@@ -11856,212 +11889,76 @@
         </node>
       </node>
     </node>
-    <node concept="1nLNMY" id="47tET_W6FC8" role="1nK1Vg">
+    <node concept="1nLNMY" id="47xL5G3eTqg" role="1nK1Vg">
       <property role="TrG5h" value="produceTypeConstraints" />
-      <node concept="3clFbS" id="47tET_W6FC9" role="1nLNMH">
-        <node concept="3SKdUt" id="47tET_W6Guf" role="3cqZAp">
-          <node concept="3SKdUq" id="47tET_W6Guh" role="3SKWNk">
-            <property role="3SKdUp" value="Produce empty Constraint set for other type variables" />
+      <node concept="3clFbS" id="47xL5G3eTqh" role="1nLNMH">
+        <node concept="3SKdUt" id="47xL5G3eTLj" role="3cqZAp">
+          <node concept="3SKdUq" id="47xL5G3eTLl" role="3SKWNk">
+            <property role="3SKdUp" value="Generalize over collected type Constraints for this type var (TVRef)" />
           </node>
         </node>
-        <node concept="1nLNNL" id="47tET_W6Gpp" role="3cqZAp">
-          <node concept="1nLNMm" id="47tET_W6Gpq" role="1nLNNK">
-            <node concept="3Aq93q" id="47tET_W6Gpy" role="1nLNMb">
-              <node concept="3I6sU6" id="47tET_W6Gpz" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_W6Gp$" role="3I6sU7">
-                  <node concept="3Aqt3T" id="47tET_W6Gp_" role="3I6s78">
-                    <ref role="3AqCNq" node="47tET_W6Fxn" resolve="produceTypeConstraints" />
-                    <node concept="1HFMs5" id="47tET_W6GpA" role="3AunhB">
-                      <node concept="ns1u0" id="47tET_W6GpC" role="1uarlW">
-                        <ref role="ns1xF" node="48ZGLP7pl6j" resolve="Cons" />
-                        <node concept="nsMwS" id="47tET_W6GpD" role="ns1xD">
-                          <ref role="nsMwP" node="48ZGLP7pl6$" resolve="head" />
-                          <node concept="1nq8_$" id="47tET_W6GpE" role="nsMwV">
-                            <node concept="a7P8L" id="47tET_XcN4f" role="1nq8_t">
-                              <ref role="a7OzE" node="47tET_XcMXL" resolve="TV" />
-                            </node>
-                          </node>
-                        </node>
-                        <node concept="nsMwS" id="47tET_W6GpG" role="ns1xD">
-                          <ref role="nsMwP" node="48ZGLP7pl6J" resolve="tail" />
-                          <node concept="1nq8_$" id="47tET_W6GpH" role="nsMwV">
-                            <node concept="a7P8L" id="47tET_XcN4i" role="1nq8_t">
-                              <ref role="a7OzE" node="47tET_XcMY0" resolve="TVsTail" />
-                            </node>
-                          </node>
-                        </node>
-                      </node>
-                      <node concept="a7P8L" id="47tET_XcN48" role="1uarlU">
-                        <ref role="a7OzE" node="47tET_XcMX_" resolve="TVs" />
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3Aq9E8" id="47tET_W6GpS" role="1nLNMd">
-              <node concept="3I6sU6" id="47tET_W6GpT" role="3Ip0Jz">
-                <node concept="3IrJb3" id="47tET_XcNpI" role="3I6sU7">
-                  <node concept="3clFbS" id="47tET_XcNpJ" role="3IrJb0">
-                    <node concept="3Aqczg" id="47tET_XcNpK" role="3cqZAp">
-                      <node concept="3Aqt3T" id="47tET_W6GpV" role="3Aqpz8">
-                        <ref role="3AqCNq" node="47tET_WOmOE" resolve="tdefConstraints" />
-                        <node concept="a7P8L" id="47tET_XcN4l" role="3AunhB">
-                          <ref role="a7OzE" node="47tET_XcMXL" resolve="TV" />
-                        </node>
-                        <node concept="a7P8L" id="47tET_XcMYE" role="3AunhB">
-                          <ref role="a7OzE" node="47tET_XcMYk" resolve="NewCtrSet" />
-                        </node>
-                      </node>
-                    </node>
-                    <node concept="3Aqczg" id="47tET_XcNpL" role="3cqZAp">
-                      <node concept="3Aqt3T" id="47tET_XcNp$" role="3Aqpz8">
-                        <ref role="3AqCNq" node="47tET_XcN9h" resolve="produceTypeConstraint" />
-                        <node concept="a7P8L" id="47tET_XcNpD" role="3AunhB">
-                          <ref role="a7OzE" node="47tET_XcMXL" resolve="TV" />
-                        </node>
-                      </node>
-                    </node>
-                    <node concept="3Aqczg" id="47tET_XcNpM" role="3cqZAp">
-                      <node concept="3Aqt3T" id="47tET_W6GpZ" role="3Aqpz8">
-                        <ref role="3AqCNq" node="47tET_W6Fxn" resolve="produceTypeConstraints" />
-                        <node concept="a7P8L" id="47tET_XcN4p" role="3AunhB">
-                          <ref role="a7OzE" node="47tET_XcMY0" resolve="TVsTail" />
-                        </node>
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="0eUR_" id="47tET_XcMXy" role="0UC6o">
-              <node concept="3NuqgR" id="47tET_XcMX$" role="0eVf_">
-                <node concept="aZer4" id="47tET_XcMX_" role="3XD1gS">
-                  <property role="TrG5h" value="TVs" />
-                </node>
-                <node concept="aZer4" id="47tET_XcMXL" role="3XD1gS">
+        <node concept="3SKdUt" id="47xL5G3eTOG" role="3cqZAp">
+          <node concept="3SKdUq" id="47xL5G3eTOI" role="3SKWNk">
+            <property role="3SKdUp" value=" i.e. make these Constraints part of its definition" />
+          </node>
+        </node>
+        <node concept="1nLNNL" id="47xL5G3eTqU" role="3cqZAp">
+          <node concept="1nLNMm" id="47xL5G3eTqV" role="1nLNNK">
+            <node concept="0eUR_" id="47xL5G3eTqW" role="0UC6o">
+              <node concept="3NuqgR" id="47xL5G3eTqX" role="0eVf_">
+                <node concept="aZer4" id="47xL5G3eTqY" role="3XD1gS">
                   <property role="TrG5h" value="TV" />
                 </node>
-                <node concept="aZer4" id="47tET_XcMY0" role="3XD1gS">
-                  <property role="TrG5h" value="TVsTail" />
+                <node concept="aZer4" id="47xL5G3eTr0" role="3XD1gS">
+                  <property role="TrG5h" value="TVRef" />
                 </node>
               </node>
-              <node concept="3NuqgR" id="47tET_XcMYj" role="0eVf_">
-                <node concept="aZer4" id="47tET_XcMYk" role="3XD1gS">
-                  <property role="TrG5h" value="NewCtrSet" />
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbH" id="47tET_XcNwp" role="3cqZAp" />
-        <node concept="1nLNNL" id="47tET_W6G$2" role="3cqZAp">
-          <node concept="1nLNMm" id="47tET_W6G$4" role="1nLNNK">
-            <node concept="3Aq93q" id="47tET_W6G_h" role="1nLNMb">
-              <node concept="3I6sU6" id="47tET_W6G_i" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_W6G_m" role="3I6sU7">
-                  <node concept="3Aqt3T" id="47tET_W6G_l" role="3I6s78">
-                    <ref role="3AqCNq" node="47tET_W6Fxn" resolve="produceTypeConstraints" />
-                    <node concept="ns1u0" id="47tET_W6G_r" role="3AunhB">
-                      <ref role="ns1xF" node="48ZGLP7pl6N" resolve="Nil" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-      </node>
-    </node>
-    <node concept="1nLNMY" id="47tET_Xf3FZ" role="1nK1Vg">
-      <property role="TrG5h" value="produceTypeConstraint" />
-      <node concept="3clFbS" id="47tET_Xf3G0" role="1nLNMH">
-        <node concept="3SKdUt" id="47tET_W6G7c" role="3cqZAp">
-          <node concept="3SKdUq" id="47tET_W6G7e" role="3SKWNk">
-            <property role="3SKdUp" value="Note: VarRef (instead of just TV) because this rule is called after freeTypeVars" />
-          </node>
-        </node>
-        <node concept="3SKdUt" id="47tET_W6Gab" role="3cqZAp">
-          <node concept="3SKdUq" id="47tET_W6Gac" role="3SKWNk">
-            <property role="3SKdUp" value="Definition Constraints must be on type vars, so reproduce Constraint set without VarRef" />
-          </node>
-        </node>
-        <node concept="1nLNNL" id="47tET_W6FKG" role="3cqZAp">
-          <node concept="1nLNMm" id="47tET_W6FKH" role="1nLNNK">
-            <node concept="0eUR_" id="47tET_W6FKL" role="0UC6o">
-              <node concept="3NuqgR" id="47tET_W6FKN" role="0eVf_">
-                <node concept="aZer4" id="47tET_Xf3Vl" role="3XD1gS">
-                  <property role="TrG5h" value="TV" />
-                </node>
-                <node concept="aZer4" id="47tET_Wcd0y" role="3XD1gS">
-                  <property role="TrG5h" value="TV0" />
-                </node>
-              </node>
-              <node concept="3NuqgR" id="47tET_W6G5G" role="0eVf_">
-                <node concept="aZer4" id="47tET_W6G5H" role="3XD1gS">
+              <node concept="3NuqgR" id="47xL5G3eTr1" role="0eVf_">
+                <node concept="aZer4" id="47xL5G3eTr2" role="3XD1gS">
                   <property role="TrG5h" value="CtrSet" />
                 </node>
               </node>
             </node>
-            <node concept="3Aq93q" id="47tET_W6FL6" role="1nLNMb">
-              <node concept="3I6sU6" id="47tET_W6FL7" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_W6FLb" role="3I6sU7">
-                  <node concept="3Aqt3T" id="47tET_W6FLa" role="3I6s78">
-                    <ref role="3AqCNq" node="47tET_XcN9h" resolve="produceTypeConstraint" />
-                    <node concept="a7P8L" id="47tET_Xf3VM" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_Xf3Vl" resolve="TV" />
+            <node concept="3Aq93q" id="47xL5G3eTr3" role="1nLNMb">
+              <node concept="3I6sU6" id="47xL5G3eTr4" role="3Ip0Jz">
+                <node concept="3I6s7M" id="47xL5G3eTr5" role="3I6sU7">
+                  <node concept="3Aqt3T" id="47xL5G3eTr6" role="3I6s78">
+                    <ref role="3AqCNq" node="47xL5G3eTpn" resolve="produceTypeConstraints" />
+                    <node concept="a7P8L" id="47xL5G3eTC1" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTr0" resolve="TVRef" />
+                    </node>
+                    <node concept="a7P8L" id="47xL5G3eTC7" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTqY" resolve="TV" />
                     </node>
                   </node>
                 </node>
               </node>
             </node>
-            <node concept="3Aq93q" id="47tET_W6FMG" role="1nLNMb">
-              <node concept="3I6sU6" id="47tET_W6FMH" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_W6G5v" role="3I6sU7">
-                  <node concept="3Aqt3T" id="47tET_W6G5u" role="3I6s78">
+            <node concept="3Aq93q" id="47xL5G3eTr8" role="1nLNMb">
+              <node concept="3I6sU6" id="47xL5G3eTr9" role="3Ip0Jz">
+                <node concept="3I6s7M" id="47xL5G3eTra" role="3I6sU7">
+                  <node concept="3Aqt3T" id="47xL5G3eTrb" role="3I6s78">
                     <ref role="3AqCNq" node="47tET_W4MQg" resolve="typeConstraints" />
-                    <node concept="ns1u0" id="47tET_W6G6i" role="3AunhB">
-                      <ref role="ns1xF" node="48ZGLP8wdTf" resolve="VarRef" />
-                      <node concept="nsMwS" id="47tET_W6G6s" role="ns1xD">
-                        <ref role="nsMwP" node="48ZGLP8wdUk" resolve="def" />
-                        <node concept="1nq8_$" id="47tET_W6G6y" role="nsMwV">
-                          <node concept="a7P8L" id="47tET_Xf3Wa" role="1nq8_t">
-                            <ref role="a7OzE" node="47tET_Wcd0y" resolve="TV0" />
-                          </node>
-                        </node>
-                      </node>
+                    <node concept="a7P8L" id="47xL5G3eTrc" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTr0" resolve="TVRef" />
                     </node>
-                    <node concept="a7P8L" id="47tET_W6G66" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_W6G5H" resolve="CtrSet" />
+                    <node concept="a7P8L" id="47xL5G3eTrd" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTr2" resolve="CtrSet" />
                     </node>
                   </node>
                 </node>
               </node>
             </node>
-            <node concept="3Aq9E8" id="47tET_W6FLm" role="1nLNMd">
-              <node concept="3I6sU6" id="47tET_W6FLn" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_W6Gn9" role="3I6sU7">
-                  <node concept="3Aqt3T" id="47tET_W6Gn8" role="3I6s78">
+            <node concept="3Aq9E8" id="47xL5G3eTre" role="1nLNMd">
+              <node concept="3I6sU6" id="47xL5G3eTrf" role="3Ip0Jz">
+                <node concept="3I6s7M" id="47xL5G3eTrg" role="3I6sU7">
+                  <node concept="3Aqt3T" id="47xL5G3eTrh" role="3I6s78">
                     <ref role="3AqCNq" node="47tET_WOmOE" resolve="tdefConstraints" />
-                    <node concept="a7P8L" id="47tET_Xf3WO" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_Xf3Vl" resolve="TV" />
+                    <node concept="a7P8L" id="47xL5G3eTri" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTqY" resolve="TV" />
                     </node>
-                    <node concept="a7P8L" id="47tET_W6Gnn" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_W6G5H" resolve="CtrSet" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3Aq9_M" id="47tET_Wcd1o" role="1nLNMa">
-              <node concept="3I6sU6" id="47tET_Wcd1p" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_Wcd1v" role="3I6sU7">
-                  <node concept="3GeI9q" id="47tET_Wcd1s" role="3I6s78">
-                    <node concept="a7P8L" id="47tET_Xf3Wu" role="3GeI8F">
-                      <ref role="a7OzE" node="47tET_Xf3Vl" resolve="TV" />
-                    </node>
-                    <node concept="a7P8L" id="47tET_Wcd1D" role="3GeI8D">
-                      <ref role="a7OzE" node="47tET_Wcd0y" resolve="TV0" />
+                    <node concept="a7P8L" id="47xL5G3eTrj" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTr2" resolve="CtrSet" />
                     </node>
                   </node>
                 </node>
@@ -12069,220 +11966,39 @@
             </node>
           </node>
         </node>
-        <node concept="3clFbH" id="47tET_XhSMg" role="3cqZAp" />
-        <node concept="1X3_iC" id="5tOHNYfUbsu" role="lGtFl">
-          <property role="3V$3am" value="statement" />
-          <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
-          <node concept="1nLNNL" id="47tET_XgGv4" role="8Wnug">
-            <node concept="1nLNMm" id="47tET_XgGv5" role="1nLNNK">
-              <node concept="0eUR_" id="47tET_XgGv6" role="0UC6o">
-                <node concept="3NuqgR" id="47tET_XgGv7" role="0eVf_">
-                  <node concept="aZer4" id="47tET_XgGv8" role="3XD1gS">
-                    <property role="TrG5h" value="TV" />
-                  </node>
-                  <node concept="aZer4" id="47tET_XgGv9" role="3XD1gS">
-                    <property role="TrG5h" value="TV0" />
-                  </node>
-                  <node concept="aZer4" id="47tET_XgGyh" role="3XD1gS">
-                    <property role="TrG5h" value="TV0Ref" />
-                  </node>
-                </node>
-                <node concept="3NuqgR" id="47tET_XgGva" role="0eVf_">
-                  <node concept="aZer4" id="47tET_XgGvb" role="3XD1gS">
-                    <property role="TrG5h" value="CtrSet" />
-                  </node>
-                </node>
-              </node>
-              <node concept="3Aq93q" id="47tET_XgGvc" role="1nLNMb">
-                <node concept="3I6sU6" id="47tET_XgGvd" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="47tET_XgGve" role="3I6sU7">
-                    <node concept="3Aqt3T" id="47tET_XgGvf" role="3I6s78">
-                      <ref role="3AqCNq" node="47tET_XcN9h" resolve="produceTypeConstraint" />
-                      <node concept="a7P8L" id="47tET_XgGvg" role="3AunhB">
-                        <ref role="a7OzE" node="47tET_XgGv8" resolve="TV" />
-                      </node>
+        <node concept="3clFbH" id="47xL5G3eTI0" role="3cqZAp" />
+        <node concept="3SKdUt" id="47xL5G3eTs1" role="3cqZAp">
+          <node concept="3SKdUq" id="47xL5G3eTs2" role="3SKWNk">
+            <property role="3SKdUp" value="For other type variables (with no Constraints on them) produce empty Constraint set" />
+          </node>
+        </node>
+        <node concept="1nLNNL" id="47xL5G3eU0t" role="3cqZAp">
+          <node concept="1nLNMm" id="47xL5G3eU0u" role="1nLNNK">
+            <node concept="3Aq93q" id="47xL5G3eU0v" role="1nLNMb">
+              <node concept="3I6sU6" id="47xL5G3eU0w" role="3Ip0Jz">
+                <node concept="3I6s7M" id="47xL5G3eU0x" role="3I6sU7">
+                  <node concept="3Aqt3T" id="47xL5G3eU0y" role="3I6s78">
+                    <ref role="3AqCNq" node="47xL5G3eTpn" resolve="produceTypeConstraints" />
+                    <node concept="a7P8L" id="47xL5G3eU35" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTr0" resolve="TVRef" />
                     </node>
-                  </node>
-                </node>
-              </node>
-              <node concept="3Aq93q" id="47tET_XgGvh" role="1nLNMb">
-                <node concept="3I6sU6" id="47tET_XgGvi" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="47tET_XgGvj" role="3I6sU7">
-                    <node concept="3Aqt3T" id="47tET_XgGvk" role="3I6s78">
-                      <ref role="3AqCNq" node="47tET_W4MQg" resolve="typeConstraints" />
-                      <node concept="a7P8L" id="47tET_XgGyZ" role="3AunhB">
-                        <ref role="a7OzE" node="47tET_XgGyh" resolve="TV0Ref" />
-                      </node>
-                      <node concept="a7P8L" id="47tET_XgGvp" role="3AunhB">
-                        <ref role="a7OzE" node="47tET_XgGvb" resolve="CtrSet" />
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-              <node concept="3Aq9E8" id="47tET_XgGvq" role="1nLNMd">
-                <node concept="3I6sU6" id="47tET_XgGvr" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="47tET_XgGvs" role="3I6sU7">
-                    <node concept="3Aqt3T" id="47tET_XgGvt" role="3I6s78">
-                      <ref role="3AqCNq" node="47tET_WOmOE" resolve="tdefConstraints" />
-                      <node concept="a7P8L" id="47tET_XgGvu" role="3AunhB">
-                        <ref role="a7OzE" node="47tET_XgGv8" resolve="TV" />
-                      </node>
-                      <node concept="a7P8L" id="47tET_XgGvv" role="3AunhB">
-                        <ref role="a7OzE" node="47tET_XgGvb" resolve="CtrSet" />
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-              <node concept="3Aq9_M" id="47tET_XgGvw" role="1nLNMa">
-                <node concept="3I6sU6" id="47tET_XgGvx" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="47tET_XgGy8" role="3I6sU7">
-                    <node concept="3A8Hvi" id="47tET_XgGy2" role="3I6s78">
-                      <node concept="ns1u0" id="47tET_XgGzE" role="3A8w4Q">
-                        <ref role="ns1xF" node="48ZGLP8wdTf" resolve="VarRef" />
-                      </node>
-                      <node concept="a7P8L" id="47tET_XgGzA" role="3A8wtg">
-                        <ref role="a7OzE" node="47tET_XgGyh" resolve="TV0Ref" />
-                      </node>
-                    </node>
-                  </node>
-                  <node concept="3I6s7M" id="47tET_XgGvy" role="3I6sU7">
-                    <node concept="3GeI9q" id="47tET_XgGvz" role="3I6s78">
-                      <node concept="a7P8L" id="47tET_XgGzN" role="3GeI8D">
-                        <ref role="a7OzE" node="47tET_XgGyh" resolve="TV0Ref" />
-                      </node>
-                      <node concept="ns1u0" id="47tET_XgGz9" role="3GeI8F">
-                        <ref role="ns1xF" node="48ZGLP8wdTf" resolve="VarRef" />
-                        <node concept="nsMwS" id="47tET_XgGzb" role="ns1xD">
-                          <ref role="nsMwP" node="48ZGLP8wdUk" resolve="def" />
-                          <node concept="1nq8_$" id="47tET_XgGzh" role="nsMwV">
-                            <node concept="a7P8L" id="47tET_XgGzf" role="1nq8_t">
-                              <ref role="a7OzE" node="47tET_XgGv8" resolve="TV" />
-                            </node>
-                          </node>
-                        </node>
-                      </node>
+                    <node concept="a7P8L" id="47xL5G3eU9A" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTqY" resolve="TV" />
                     </node>
                   </node>
                 </node>
               </node>
             </node>
-          </node>
-        </node>
-        <node concept="3clFbH" id="47tET_WgaOO" role="3cqZAp" />
-        <node concept="3SKdUt" id="47tET_WgaMq" role="3cqZAp">
-          <node concept="3SKdUq" id="47tET_WgaQA" role="3SKWNk">
-            <property role="3SKdUp" value="Do nothing on type vars with typeConstraints on them" />
-          </node>
-        </node>
-        <node concept="3SKdUt" id="47tET_WgaVf" role="3cqZAp">
-          <node concept="3SKdUq" id="47tET_WgaVh" role="3SKWNk">
-            <property role="3SKdUp" value="This case can happen when type scheme is inst-d and then again gen-d" />
-          </node>
-        </node>
-        <node concept="1nLNNL" id="47tET_WgaMs" role="3cqZAp">
-          <node concept="1nLNMm" id="47tET_WgaMt" role="1nLNNK">
-            <node concept="3Aq93q" id="47tET_WgaMu" role="1nLNMb">
-              <node concept="3I6sU6" id="47tET_WgaMv" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_WgaMw" role="3I6sU7">
-                  <node concept="3Aqt3T" id="47tET_WgaMx" role="3I6s78">
-                    <ref role="3AqCNq" node="47tET_XcN9h" resolve="produceTypeConstraint" />
-                    <node concept="a7P8L" id="47tET_Xf3X9" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_Xf3Vl" resolve="TV" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3Aq93q" id="47tET_WgaQQ" role="1nLNMb">
-              <node concept="3I6sU6" id="47tET_WgaQR" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_WgaR8" role="3I6sU7">
-                  <node concept="3Aqt3T" id="47tET_WgaR7" role="3I6s78">
-                    <ref role="3AqCNq" node="47tET_W4MQg" resolve="typeConstraints" />
-                    <node concept="a7P8L" id="47tET_WgaRd" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_Wcd0y" resolve="TV0" />
-                    </node>
-                    <node concept="a7P8L" id="47tET_WgaRl" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_W6G5H" resolve="CtrSet" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3Aq9E8" id="47tET_WgaMF" role="1nLNMd">
-              <node concept="3I6sU6" id="47tET_WgaMG" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_WOmPn" role="3I6sU7">
-                  <node concept="3Aqt3T" id="47tET_WOmPl" role="3I6s78">
+            <node concept="3Aq9E8" id="47xL5G3eU0E" role="1nLNMd">
+              <node concept="3I6sU6" id="47xL5G3eU0F" role="3Ip0Jz">
+                <node concept="3I6s7M" id="47xL5G3eU0G" role="3I6sU7">
+                  <node concept="3Aqt3T" id="47xL5G3eU0H" role="3I6s78">
                     <ref role="3AqCNq" node="47tET_WOmOE" resolve="tdefConstraints" />
-                    <node concept="a7P8L" id="47tET_Xf3Yj" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_Wcd0y" resolve="TV0" />
+                    <node concept="a7P8L" id="47xL5G3eU9Q" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTqY" resolve="TV" />
                     </node>
-                    <node concept="a7P8L" id="47tET_WOmPB" role="3AunhB">
-                      <ref role="a7OzE" node="47tET_W6G5H" resolve="CtrSet" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="3Aq9_M" id="47tET_WgaQE" role="1nLNMa">
-              <node concept="3I6sU6" id="47tET_WgaQF" role="3Ip0Jz">
-                <node concept="3I6s7M" id="47tET_XgaKb" role="3I6sU7">
-                  <node concept="2aLmEc" id="47tET_XgaK9" role="3I6s78">
-                    <node concept="a7P8L" id="47tET_XgaKm" role="2aLmnP">
-                      <ref role="a7OzE" node="47tET_Wcd0y" resolve="TV0" />
-                    </node>
-                  </node>
-                </node>
-                <node concept="3I6s7M" id="47tET_WgaSm" role="3I6sU7">
-                  <node concept="3GeI9q" id="47tET_WgaSg" role="3I6s78">
-                    <node concept="a7P8L" id="47tET_Xf3Xr" role="3GeI8F">
-                      <ref role="a7OzE" node="47tET_Xf3Vl" resolve="TV" />
-                    </node>
-                    <node concept="a7P8L" id="47tET_Xf3XF" role="3GeI8D">
-                      <ref role="a7OzE" node="47tET_Wcd0y" resolve="TV0" />
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-          </node>
-        </node>
-        <node concept="3clFbH" id="47tET_Xk9CE" role="3cqZAp" />
-        <node concept="3SKdUt" id="47tET_Xk9Gf" role="3cqZAp">
-          <node concept="3SKdUq" id="47tET_Xk9Gh" role="3SKWNk">
-            <property role="3SKdUp" value="Produce empty constraint set for other variables" />
-          </node>
-        </node>
-        <node concept="1X3_iC" id="47tET_Xk9Mu" role="lGtFl">
-          <property role="3V$3am" value="statement" />
-          <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
-          <node concept="1nLNNL" id="47tET_Xk9JU" role="8Wnug">
-            <node concept="1nLNMm" id="47tET_Xk9JW" role="1nLNNK">
-              <node concept="3Aq93q" id="47tET_Xk9LN" role="1nLNMb">
-                <property role="3ArMco" value="true" />
-                <node concept="3I6sU6" id="47tET_Xk9LO" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="47tET_Xk9LS" role="3I6sU7">
-                    <node concept="3Aqt3T" id="47tET_Xk9LR" role="3I6s78">
-                      <ref role="3AqCNq" node="47tET_XcN9h" resolve="produceTypeConstraint" />
-                      <node concept="a7P8L" id="47tET_Xk9LX" role="3AunhB">
-                        <ref role="a7OzE" node="47tET_Xf3Vl" resolve="TV" />
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-              <node concept="3Aq9E8" id="47tET_Xk9M2" role="1nLNMd">
-                <node concept="3I6sU6" id="47tET_Xk9M3" role="3Ip0Jz">
-                  <node concept="3I6s7M" id="47tET_Xk9M7" role="3I6sU7">
-                    <node concept="3Aqt3T" id="47tET_Xk9M6" role="3I6s78">
-                      <ref role="3AqCNq" node="47tET_WOmOE" resolve="tdefConstraints" />
-                      <node concept="a7P8L" id="47tET_Xk9Mg" role="3AunhB">
-                        <ref role="a7OzE" node="47tET_Xf3Vl" resolve="TV" />
-                      </node>
-                      <node concept="a7P8L" id="47tET_Xk9Mo" role="3AunhB">
-                        <ref role="a7OzE" node="47tET_W6G5H" resolve="CtrSet" />
-                      </node>
+                    <node concept="a7P8L" id="47xL5G3eU9G" role="3AunhB">
+                      <ref role="a7OzE" node="47xL5G3eTr2" resolve="CtrSet" />
                     </node>
                   </node>
                 </node>
@@ -12710,7 +12426,12 @@
         </node>
         <node concept="3SKdUt" id="47tET_WhdA1" role="3cqZAp">
           <node concept="3SKdUq" id="47tET_WhdA2" role="3SKWNk">
-            <property role="3SKdUp" value="which has its own Constraints -- they must be stronger (more restrictive) (see c1, qq_lb4 test cases)" />
+            <property role="3SKdUp" value=" which has its own Constraints -- they must be stronger (more restrictive)" />
+          </node>
+        </node>
+        <node concept="3SKdUt" id="47xL5G3lRcb" role="3cqZAp">
+          <node concept="3SKdUq" id="47xL5G3lRcc" role="3SKWNk">
+            <property role="3SKdUp" value=" (see c1, qq_lb4 test cases)" />
           </node>
         </node>
         <node concept="1nLNNL" id="47tET_Wh5p8" role="3cqZAp">
@@ -13009,6 +12730,11 @@
           </node>
         </node>
         <node concept="3clFbH" id="47tET_WsEvf" role="3cqZAp" />
+        <node concept="3SKdUt" id="47xL5G3lR08" role="3cqZAp">
+          <node concept="3SKdUq" id="47xL5G3lR0a" role="3SKWNk">
+            <property role="3SKdUp" value="Just a list traverse" />
+          </node>
+        </node>
         <node concept="1nLNNL" id="47tET_WsEw4" role="3cqZAp">
           <node concept="1nLNMm" id="47tET_WsEw6" role="1nLNNK">
             <node concept="3Aq93q" id="47tET_WsEwz" role="1nLNMb">
@@ -13051,43 +12777,6 @@
               <node concept="3I6sU6" id="47tET_WsEyj" role="3Ip0Jz">
                 <node concept="3IrJb3" id="47tET_WsEJB" role="3I6sU7">
                   <node concept="3clFbS" id="47tET_WsEJC" role="3IrJb0">
-                    <node concept="1X3_iC" id="47tET_W_5tK" role="lGtFl">
-                      <property role="3V$3am" value="statement" />
-                      <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
-                      <node concept="3Aqczg" id="47tET_WsEJD" role="8Wnug">
-                        <node concept="3A8Hvi" id="47tET_WsEHq" role="3Aqpz8">
-                          <node concept="a7P8L" id="47tET_WsEOB" role="3A8wtg">
-                            <ref role="a7OzE" node="47tET_WsENT" resolve="Ctr" />
-                          </node>
-                          <node concept="ns1u0" id="47tET_WsEHI" role="3A8w4Q">
-                            <ref role="ns1xF" node="3vXKzDNDVgC" resolve="Constraint" />
-                            <node concept="nsMwS" id="47tET_WsEHK" role="ns1xD">
-                              <ref role="nsMwP" node="47tET_W4Sc3" resolve="typeclass" />
-                              <node concept="1nq8_$" id="47tET_WsEHQ" role="nsMwV">
-                                <node concept="a7P8L" id="47tET_WsEHO" role="1nq8_t">
-                                  <ref role="a7OzE" node="47tET_WsEB1" resolve="TcPtr" />
-                                </node>
-                              </node>
-                            </node>
-                          </node>
-                        </node>
-                      </node>
-                    </node>
-                    <node concept="1X3_iC" id="47tET_W_5uL" role="lGtFl">
-                      <property role="3V$3am" value="statement" />
-                      <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
-                      <node concept="3Aqczg" id="47tET_WsEJE" role="8Wnug">
-                        <node concept="3Aqt3T" id="47tET_WsEIy" role="3Aqpz8">
-                          <ref role="3AqCNq" node="47tET_WsED9" resolve="checkSingleInstance" />
-                          <node concept="a7P8L" id="47tET_WsEJ0" role="3AunhB">
-                            <ref role="a7OzE" node="47tET_WsErV" resolve="Type" />
-                          </node>
-                          <node concept="a7P8L" id="47tET_WsEJu" role="3AunhB">
-                            <ref role="a7OzE" node="47tET_WsEB1" resolve="TcPtr" />
-                          </node>
-                        </node>
-                      </node>
-                    </node>
                     <node concept="3Aqczg" id="47tET_W_5$i" role="3cqZAp">
                       <node concept="3Aqt3T" id="47tET_W_5$j" role="3Aqpz8">
                         <ref role="3AqCNq" node="47tET_WsED9" resolve="checkSingleInstance" />
@@ -13115,12 +12804,6 @@
               </node>
             </node>
             <node concept="0eUR_" id="47tET_WsEAY" role="0UC6o">
-              <node concept="3NuqgR" id="47tET_WsEB0" role="0eVf_">
-                <node concept="aZer4" id="47tET_WsEB1" role="3XD1gS">
-                  <property role="TrG5h" value="TcPtr" />
-                </node>
-                <node concept="2sp9CU" id="47tET_WsEHX" role="3vLBG7" />
-              </node>
               <node concept="3NuqgR" id="47tET_WsENS" role="0eVf_">
                 <node concept="aZer4" id="47tET_WsENT" role="3XD1gS">
                   <property role="TrG5h" value="Ctr" />
@@ -13138,6 +12821,11 @@
             <property role="3SKdUp" value="Try to match Type against Instance's type scheme" />
           </node>
         </node>
+        <node concept="3SKdUt" id="47xL5G3lR4V" role="3cqZAp">
+          <node concept="3SKdUq" id="47xL5G3lR4X" role="3SKWNk">
+            <property role="3SKdUp" value="If satisfying instance is found -- then instanceCheck succeeded" />
+          </node>
+        </node>
         <node concept="1nLNNL" id="47tET_WsEFV" role="3cqZAp">
           <node concept="1nLNMm" id="47tET_WsEFX" role="1nLNNK">
             <node concept="3Aq93q" id="47tET_WsEGY" role="1nLNMb">
@@ -13219,6 +12907,29 @@
         <node concept="3clFbH" id="47tET_WsEP0" role="3cqZAp" />
         <node concept="1nLNNL" id="47tET_WFhPa" role="3cqZAp">
           <node concept="1nLNMm" id="47tET_WFhPc" role="1nLNNK">
+            <node concept="3Aq9E8" id="47xL5G3gmXn" role="1nLNMd">
+              <node concept="3I6sU6" id="47xL5G3gmXo" role="3Ip0Jz">
+                <node concept="3IrJb3" id="47xL5G3gmXD" role="3I6sU7">
+                  <node concept="3clFbS" id="47xL5G3gmXE" role="3IrJb0">
+                    <node concept="3SKdUt" id="47xL5G3gmXS" role="3cqZAp">
+                      <node concept="3SKdUq" id="47xL5G3gmXU" role="3SKWNk">
+                        <property role="3SKdUp" value="Unification will trigger recursive check for type Constraints (if there're some)" />
+                      </node>
+                    </node>
+                    <node concept="3Aqczg" id="47xL5G3gmXF" role="3cqZAp">
+                      <node concept="3A8Hvi" id="47xL5G3gmXr" role="3Aqpz8">
+                        <node concept="a7P8L" id="47xL5G3gmXz" role="3A8wtg">
+                          <ref role="a7OzE" node="47tET_WsErV" resolve="Type" />
+                        </node>
+                        <node concept="a7P8L" id="47xL5G3gmXA" role="3A8w4Q">
+                          <ref role="a7OzE" node="47tET_WE8Qa" resolve="I" />
+                        </node>
+                      </node>
+                    </node>
+                  </node>
+                </node>
+              </node>
+            </node>
             <node concept="3Aq93q" id="47tET_WFhRe" role="1nLNMb">
               <node concept="3I6sU6" id="47tET_WFhRf" role="3Ip0Jz">
                 <node concept="3I6s7M" id="47tET_WFhRj" role="3I6sU7">
diff --git a/samples/lambdacalc/solutions/samples.lambdacalc.demo/models/samples.lambdacalc.demo.mps b/samples/lambdacalc/solutions/samples.lambdacalc.demo/models/samples.lambdacalc.demo.mps
index c9cbefbd..0588a427 100644
--- a/samples/lambdacalc/solutions/samples.lambdacalc.demo/models/samples.lambdacalc.demo.mps
+++ b/samples/lambdacalc/solutions/samples.lambdacalc.demo/models/samples.lambdacalc.demo.mps
@@ -2208,6 +2208,9 @@
                   <node concept="t0$VC" id="48ZGLP8pFrZ" role="1DVIo4">
                     <ref role="t0$VJ" node="JqEP$8s1kx" resolve="g" />
                   </node>
+                  <node concept="1U20sH" id="47xL5G3iXBz" role="lGtFl">
+                    <property role="1U20sK" value="error" />
+                  </node>
                 </node>
                 <node concept="1DVIo5" id="48ZGLP8pFss" role="3EUmh">
                   <node concept="3EUms" id="48ZGLP8pFsH" role="1DVIo8">
@@ -2217,9 +2220,6 @@
                   <node concept="t0$VC" id="48ZGLP8pFsn" role="1DVIo4">
                     <ref role="t0$VJ" node="JqEP$8s1kx" resolve="g" />
                   </node>
-                  <node concept="1U20sH" id="1IKbs5XIGbZ" role="lGtFl">
-                    <property role="1U20sK" value="error" />
-                  </node>
                 </node>
               </node>
             </node>
@@ -4534,6 +4534,9 @@
                       <property role="TrG5h" value="d" />
                     </node>
                   </node>
+                  <node concept="1U20sH" id="47xL5G3gi4a" role="lGtFl">
+                    <property role="1U20sK" value="error" />
+                  </node>
                 </node>
               </node>
               <node concept="1DVIo5" id="47tET_Whdej" role="3EUmh">
@@ -4607,146 +4610,147 @@
             </node>
           </node>
         </node>
-        <node concept="1U20sH" id="47tET_Xpa$f" role="lGtFl">
-          <property role="1U20sK" value="error" />
-        </node>
       </node>
     </node>
-    <node concept="1DVJbV" id="47tET_Whdid" role="1DVIru">
-      <node concept="1DVIrG" id="47tET_Whdie" role="j9CMd">
-        <node concept="1DVIrU" id="47tET_Whdif" role="1DVIrD">
-          <node concept="1DVIrB" id="47tET_Whdig" role="1DVIr_">
-            <node concept="1DVIoH" id="47tET_Whdih" role="1DVIrA">
-              <property role="TrG5h" value="x" />
+    <node concept="1X3_iC" id="47xL5G3jgRB" role="lGtFl">
+      <property role="3V$3am" value="clause" />
+      <property role="3V$3ak" value="af858d84-85f2-42f4-a854-0b3c6b5cd482/8739282858702982568/8739282858702982571" />
+      <node concept="1DVJbV" id="47tET_Whdid" role="8Wnug">
+        <node concept="1DVIrG" id="47tET_Whdie" role="j9CMd">
+          <node concept="1DVIrU" id="47tET_Whdif" role="1DVIrD">
+            <node concept="1DVIrB" id="47tET_Whdig" role="1DVIr_">
+              <node concept="1DVIoH" id="47tET_Whdih" role="1DVIrA">
+                <property role="TrG5h" value="x" />
+              </node>
             </node>
-          </node>
-          <node concept="1DVIrU" id="47tET_Whdii" role="1DVIrw">
-            <node concept="1DVIrB" id="47tET_Whdij" role="1DVIr_">
-              <node concept="3TPQf" id="47tET_Whdik" role="1DVIrA">
-                <node concept="1DVIoH" id="47tET_Whdil" role="3TPQ0">
-                  <property role="TrG5h" value="g" />
-                </node>
-                <node concept="3JbUGG" id="47tET_Whdim" role="3TPQk">
-                  <node concept="1jz_ff" id="47tET_Whdio" role="3JbKvY">
-                    <node concept="3EVAj" id="47tET_Whdip" role="1jz_f_">
-                      <node concept="aFS0r" id="47tET_Whdiq" role="3EVAi">
+            <node concept="1DVIrU" id="47tET_Whdii" role="1DVIrw">
+              <node concept="1DVIrB" id="47tET_Whdij" role="1DVIr_">
+                <node concept="3TPQf" id="47tET_Whdik" role="1DVIrA">
+                  <node concept="1DVIoH" id="47tET_Whdil" role="3TPQ0">
+                    <property role="TrG5h" value="g" />
+                  </node>
+                  <node concept="3JbUGG" id="47tET_Whdim" role="3TPQk">
+                    <node concept="1jz_ff" id="47tET_Whdio" role="3JbKvY">
+                      <node concept="3EVAj" id="47tET_Whdip" role="1jz_f_">
+                        <node concept="aFS0r" id="47tET_Whdiq" role="3EVAi">
+                          <ref role="aFS0e" node="47tET_Whdit" resolve="b" />
+                        </node>
+                        <node concept="aFS0r" id="47tET_Whdir" role="3EVAk">
+                          <ref role="aFS0e" node="47tET_Whdiu" resolve="c" />
+                        </node>
+                      </node>
+                      <node concept="aFS0r" id="47tET_Whdis" role="1jz_fp">
                         <ref role="aFS0e" node="47tET_Whdit" resolve="b" />
                       </node>
-                      <node concept="aFS0r" id="47tET_Whdir" role="3EVAk">
-                        <ref role="aFS0e" node="47tET_Whdiu" resolve="c" />
-                      </node>
                     </node>
-                    <node concept="aFS0r" id="47tET_Whdis" role="1jz_fp">
-                      <ref role="aFS0e" node="47tET_Whdit" resolve="b" />
+                    <node concept="2BbKIm" id="47tET_Whdit" role="5lUUh">
+                      <property role="TrG5h" value="b" />
+                    </node>
+                    <node concept="2BbKIm" id="47tET_Whdiu" role="5lUUh">
+                      <property role="TrG5h" value="c" />
                     </node>
-                  </node>
-                  <node concept="2BbKIm" id="47tET_Whdit" role="5lUUh">
-                    <property role="TrG5h" value="b" />
-                  </node>
-                  <node concept="2BbKIm" id="47tET_Whdiu" role="5lUUh">
-                    <property role="TrG5h" value="c" />
                   </node>
                 </node>
               </node>
-            </node>
-            <node concept="3EUms" id="47tET_Whdiv" role="1DVIrw">
-              <node concept="1DVIo5" id="47tET_Whdiw" role="3EUmv">
-                <node concept="3P8L2H" id="47tET_Whdix" role="1DVIo8" />
-                <node concept="3TPRf" id="47tET_Whdiy" role="1DVIo4">
-                  <node concept="t0$VC" id="47tET_Whdiz" role="3TPR0">
-                    <ref role="t0$VJ" node="47tET_Whdik" resolve="g" />
-                  </node>
-                  <node concept="3JbUGG" id="47tET_Whdi$" role="3TPQk">
-                    <node concept="1jz_ff" id="47tET_Whdi_" role="3JbKvY">
-                      <node concept="aFS0r" id="47tET_WhdiA" role="1jz_fp">
-                        <ref role="aFS0e" node="47tET_WhdiE" resolve="d" />
-                      </node>
-                      <node concept="3EVAj" id="47tET_WhdiB" role="1jz_f_">
-                        <node concept="aFS0r" id="47tET_WhdiC" role="3EVAi">
+              <node concept="3EUms" id="47tET_Whdiv" role="1DVIrw">
+                <node concept="1DVIo5" id="47tET_Whdiw" role="3EUmv">
+                  <node concept="3P8L2H" id="47tET_Whdix" role="1DVIo8" />
+                  <node concept="3TPRf" id="47tET_Whdiy" role="1DVIo4">
+                    <node concept="t0$VC" id="47tET_Whdiz" role="3TPR0">
+                      <ref role="t0$VJ" node="47tET_Whdik" resolve="g" />
+                    </node>
+                    <node concept="3JbUGG" id="47tET_Whdi$" role="3TPQk">
+                      <node concept="1jz_ff" id="47tET_Whdi_" role="3JbKvY">
+                        <node concept="aFS0r" id="47tET_WhdiA" role="1jz_fp">
                           <ref role="aFS0e" node="47tET_WhdiE" resolve="d" />
                         </node>
-                        <node concept="aFS0r" id="47tET_WhdiD" role="3EVAk">
-                          <ref role="aFS0e" node="47tET_Whdj8" resolve="a" />
+                        <node concept="3EVAj" id="47tET_WhdiB" role="1jz_f_">
+                          <node concept="aFS0r" id="47tET_WhdiC" role="3EVAi">
+                            <ref role="aFS0e" node="47tET_WhdiE" resolve="d" />
+                          </node>
+                          <node concept="aFS0r" id="47tET_WhdiD" role="3EVAk">
+                            <ref role="aFS0e" node="47tET_Whdj8" resolve="a" />
+                          </node>
+                        </node>
+                      </node>
+                      <node concept="2BbKIm" id="47tET_WhdiE" role="5lUUh">
+                        <property role="TrG5h" value="d" />
+                      </node>
+                    </node>
+                  </node>
+                </node>
+                <node concept="1DVIo5" id="47tET_WhdiF" role="3EUmh">
+                  <node concept="t0$VC" id="47tET_WhdiG" role="1DVIo4">
+                    <ref role="t0$VJ" node="47tET_Whdik" resolve="g" />
+                  </node>
+                  <node concept="3EUms" id="47tET_WhdiH" role="1DVIo8">
+                    <node concept="3P8MHP" id="47tET_WhdiI" role="3EUmv" />
+                    <node concept="3P8MHP" id="47tET_WhdiJ" role="3EUmh" />
+                  </node>
+                </node>
+              </node>
+            </node>
+          </node>
+          <node concept="3TPQf" id="47tET_WhdiK" role="1DVIrJ">
+            <node concept="1DVIoH" id="47tET_WhdiL" role="3TPQ0">
+              <property role="TrG5h" value="qq_lb4" />
+            </node>
+            <node concept="3JbUGG" id="47tET_WhdiM" role="3TPQk">
+              <node concept="1FkZV4" id="47tET_WhdiN" role="1FkZ4g">
+                <ref role="1FvTW1" node="47tET_Whdj8" resolve="a" />
+                <ref role="1FkZV7" node="47tET_Wha9b" resolve="C1" />
+              </node>
+              <node concept="1jz_ff" id="47tET_WhdiO" role="3JbKvY">
+                <node concept="aFS0r" id="47tET_WhdiP" role="1jz_fp">
+                  <ref role="aFS0e" node="47tET_Whdj8" resolve="a" />
+                </node>
+                <node concept="1jz_ff" id="47tET_WhdiQ" role="1jz_f_">
+                  <node concept="3EVAj" id="47tET_WhdiR" role="1jz_f_">
+                    <node concept="3EVAj" id="47tET_WhdiS" role="3EVAk">
+                      <node concept="aFS0r" id="47tET_WhdiT" role="3EVAk">
+                        <ref role="aFS0e" node="47tET_Whdj8" resolve="a" />
+                      </node>
+                      <node concept="3P8Jbz" id="47tET_WhdiU" role="3EVAi" />
+                    </node>
+                    <node concept="3EVAj" id="47tET_WhdiV" role="3EVAi">
+                      <node concept="aFS0r" id="47tET_WhdiW" role="3EVAk">
+                        <ref role="aFS0e" node="47tET_Whdj8" resolve="a" />
+                      </node>
+                      <node concept="3EVAj" id="47tET_WhdiX" role="3EVAi">
+                        <node concept="3P8Jbz" id="47tET_WhdiY" role="3EVAk" />
+                        <node concept="3P8Jbz" id="47tET_WhdiZ" role="3EVAi" />
+                      </node>
+                    </node>
+                  </node>
+                  <node concept="3JbUGG" id="47tET_Whdj0" role="1jz_fp">
+                    <node concept="2BbKIm" id="47tET_Whdj1" role="5lUUh">
+                      <property role="TrG5h" value="b" />
+                    </node>
+                    <node concept="2BbKIm" id="47tET_Whdj2" role="5lUUh">
+                      <property role="TrG5h" value="c" />
+                    </node>
+                    <node concept="1jz_ff" id="47tET_Whdj3" role="3JbKvY">
+                      <node concept="aFS0r" id="47tET_Whdj4" role="1jz_fp">
+                        <ref role="aFS0e" node="47tET_Whdj1" resolve="b" />
+                      </node>
+                      <node concept="3EVAj" id="47tET_Whdj5" role="1jz_f_">
+                        <node concept="aFS0r" id="47tET_Whdj6" role="3EVAi">
+                          <ref role="aFS0e" node="47tET_Whdj1" resolve="b" />
+                        </node>
+                        <node concept="aFS0r" id="47tET_Whdj7" role="3EVAk">
+                          <ref role="aFS0e" node="47tET_Whdj2" resolve="c" />
                         </node>
                       </node>
                     </node>
-                    <node concept="2BbKIm" id="47tET_WhdiE" role="5lUUh">
-                      <property role="TrG5h" value="d" />
-                    </node>
                   </node>
                 </node>
               </node>
-              <node concept="1DVIo5" id="47tET_WhdiF" role="3EUmh">
-                <node concept="t0$VC" id="47tET_WhdiG" role="1DVIo4">
-                  <ref role="t0$VJ" node="47tET_Whdik" resolve="g" />
-                </node>
-                <node concept="3EUms" id="47tET_WhdiH" role="1DVIo8">
-                  <node concept="3P8MHP" id="47tET_WhdiI" role="3EUmv" />
-                  <node concept="3P8MHP" id="47tET_WhdiJ" role="3EUmh" />
-                </node>
+              <node concept="2BbKIm" id="47tET_Whdj8" role="5lUUh">
+                <property role="TrG5h" value="a" />
               </node>
             </node>
           </node>
         </node>
-        <node concept="3TPQf" id="47tET_WhdiK" role="1DVIrJ">
-          <node concept="1DVIoH" id="47tET_WhdiL" role="3TPQ0">
-            <property role="TrG5h" value="qq_lb4" />
-          </node>
-          <node concept="3JbUGG" id="47tET_WhdiM" role="3TPQk">
-            <node concept="1FkZV4" id="47tET_WhdiN" role="1FkZ4g">
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-              <ref role="1FkZV7" node="47tET_Wha9b" resolve="C1" />
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-                <node concept="3EVAj" id="47tET_WhdiR" role="1jz_f_">
-                  <node concept="3EVAj" id="47tET_WhdiS" role="3EVAk">
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-                    <node concept="3P8Jbz" id="47tET_WhdiU" role="3EVAi" />
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-                  <node concept="3EVAj" id="47tET_WhdiV" role="3EVAi">
-                    <node concept="aFS0r" id="47tET_WhdiW" role="3EVAk">
-                      <ref role="aFS0e" node="47tET_Whdj8" resolve="a" />
-                    </node>
-                    <node concept="3EVAj" id="47tET_WhdiX" role="3EVAi">
-                      <node concept="3P8Jbz" id="47tET_WhdiY" role="3EVAk" />
-                      <node concept="3P8Jbz" id="47tET_WhdiZ" role="3EVAi" />
-                    </node>
-                  </node>
-                </node>
-                <node concept="3JbUGG" id="47tET_Whdj0" role="1jz_fp">
-                  <node concept="2BbKIm" id="47tET_Whdj1" role="5lUUh">
-                    <property role="TrG5h" value="b" />
-                  </node>
-                  <node concept="2BbKIm" id="47tET_Whdj2" role="5lUUh">
-                    <property role="TrG5h" value="c" />
-                  </node>
-                  <node concept="1jz_ff" id="47tET_Whdj3" role="3JbKvY">
-                    <node concept="aFS0r" id="47tET_Whdj4" role="1jz_fp">
-                      <ref role="aFS0e" node="47tET_Whdj1" resolve="b" />
-                    </node>
-                    <node concept="3EVAj" id="47tET_Whdj5" role="1jz_f_">
-                      <node concept="aFS0r" id="47tET_Whdj6" role="3EVAi">
-                        <ref role="aFS0e" node="47tET_Whdj1" resolve="b" />
-                      </node>
-                      <node concept="aFS0r" id="47tET_Whdj7" role="3EVAk">
-                        <ref role="aFS0e" node="47tET_Whdj2" resolve="c" />
-                      </node>
-                    </node>
-                  </node>
-                </node>
-              </node>
-            </node>
-            <node concept="2BbKIm" id="47tET_Whdj8" role="5lUUh">
-              <property role="TrG5h" value="a" />
-            </node>
-          </node>
-        </node>
       </node>
     </node>
     <node concept="1FkZNw" id="2O9ahh6znzy" role="1DVIru">
@@ -4938,6 +4942,9 @@
               <node concept="3P8L2H" id="47tET_WwVsa" role="3EUmv" />
               <node concept="3P8L2H" id="47tET_WwVsc" role="3EUmh" />
             </node>
+            <node concept="1U20sH" id="47xL5G3iI7i" role="lGtFl">
+              <property role="1U20sK" value="error" />
+            </node>
           </node>
           <node concept="3EUms" id="47tET_WwVs0" role="1DVIo8">
             <node concept="3P8L2H" id="47tET_WwVs2" role="3EUmv" />
@@ -4949,7 +4956,7 @@
     <node concept="1DVJbV" id="47tET_WwVeW" role="1DVIru">
       <node concept="1DVIrG" id="47tET_WwVeX" role="j9CMd">
         <node concept="1DVIoH" id="47tET_WwVeY" role="1DVIrJ">
-          <property role="TrG5h" value="ii2" />
+          <property role="TrG5h" value="ii2bool" />
         </node>
         <node concept="1DVIo5" id="47tET_WwVeZ" role="1DVIrD">
           <node concept="1DVIo5" id="47tET_WwVf0" role="1DVIo4">
@@ -4979,7 +4986,7 @@
     <node concept="1DVJbV" id="47tET_WwV6e" role="1DVIru">
       <node concept="1DVIrG" id="47tET_WwV6f" role="j9CMd">
         <node concept="1DVIoH" id="47tET_WwV6g" role="1DVIrJ">
-          <property role="TrG5h" value="ii2_bad" />
+          <property role="TrG5h" value="ii2free" />
         </node>
         <node concept="1DVIo5" id="47tET_WwV6h" role="1DVIrD">
           <node concept="1DVIo5" id="47tET_WwV6j" role="1DVIo4">
@@ -4996,9 +5003,6 @@
                 <ref role="t0$VJ" node="47tET_WwVda" resolve="x" />
               </node>
             </node>
-            <node concept="1U20sH" id="47tET_XliIO" role="lGtFl">
-              <property role="1U20sK" value="error" />
-            </node>
           </node>
           <node concept="1DVIrU" id="47tET_WwVdg" role="1DVIo8">
             <node concept="1DVIrB" id="47tET_WwVdh" role="1DVIr_">
@@ -5016,7 +5020,7 @@
     <node concept="1DVJbV" id="47tET_Xliiq" role="1DVIru">
       <node concept="1DVIrG" id="47tET_Xliir" role="j9CMd">
         <node concept="1DVIoH" id="47tET_Xliis" role="1DVIrJ">
-          <property role="TrG5h" value="ii2a" />
+          <property role="TrG5h" value="ii2anno" />
         </node>
         <node concept="1DVIo5" id="47tET_Xliit" role="1DVIrD">
           <node concept="1DVIo5" id="47tET_Xliiu" role="1DVIo4">
@@ -5078,7 +5082,7 @@
     <node concept="1DVJbV" id="47tET_XliM6" role="1DVIru">
       <node concept="1DVIrG" id="47tET_XliM7" role="j9CMd">
         <node concept="1DVIoH" id="47tET_XliM8" role="1DVIrJ">
-          <property role="TrG5h" value="ii3" />
+          <property role="TrG5h" value="ii3bool" />
         </node>
         <node concept="1DVIo5" id="47tET_XliM9" role="1DVIrD">
           <node concept="1DVIo5" id="47tET_XliMa" role="1DVIo4">
@@ -5129,7 +5133,7 @@
     <node concept="1DVJbV" id="47tET_XljbM" role="1DVIru">
       <node concept="1DVIrG" id="47tET_XljbN" role="j9CMd">
         <node concept="1DVIoH" id="47tET_XljbO" role="1DVIrJ">
-          <property role="TrG5h" value="ii3_bad" />
+          <property role="TrG5h" value="ii3free" />
         </node>
         <node concept="1DVIo5" id="47tET_XljbP" role="1DVIrD">
           <node concept="1DVIo5" id="47tET_XljbQ" role="1DVIo4">
@@ -5177,15 +5181,12 @@
             </node>
           </node>
         </node>
-        <node concept="1U20sH" id="47tET_XpfVS" role="lGtFl">
-          <property role="1U20sK" value="error" />
-        </node>
       </node>
     </node>
     <node concept="1DVJbV" id="47tET_Xljn5" role="1DVIru">
       <node concept="1DVIrG" id="47tET_Xljn6" role="j9CMd">
         <node concept="1DVIoH" id="47tET_Xljn7" role="1DVIrJ">
-          <property role="TrG5h" value="ii3a_unclear" />
+          <property role="TrG5h" value="ii3anno_unclear" />
         </node>
         <node concept="1DVIo5" id="47tET_Xljn8" role="1DVIrD">
           <node concept="1DVIo5" id="47tET_Xljn9" role="1DVIo4">
@@ -5257,7 +5258,7 @@
     <node concept="1DVJbV" id="47tET_Xliwm" role="1DVIru">
       <node concept="1DVIrG" id="47tET_Xliwn" role="j9CMd">
         <node concept="1DVIoH" id="47tET_Xliwo" role="1DVIrJ">
-          <property role="TrG5h" value="ii4" />
+          <property role="TrG5h" value="ii4_bad" />
         </node>
         <node concept="1DVIo5" id="47tET_Xliwp" role="1DVIrD">
           <node concept="1DVIo5" id="47tET_Xliwq" role="1DVIo4">
@@ -5288,6 +5289,9 @@
                 </node>
               </node>
             </node>
+            <node concept="1U20sH" id="47xL5G3h3nw" role="lGtFl">
+              <property role="1U20sK" value="error" />
+            </node>
           </node>
           <node concept="1DVIrU" id="47tET_Xliw_" role="1DVIo8">
             <node concept="1DVIrB" id="47tET_XliwA" role="1DVIr_">
@@ -5811,5 +5815,322 @@
       </node>
     </node>
   </node>
+  <node concept="1DVIrt" id="47xL5G3jc4X">
+    <property role="TrG5h" value="TypeclassesTest2" />
+    <node concept="1FkZNM" id="47xL5G3jc4Y" role="1DVIru">
+      <property role="TrG5h" value="Monoid3" />
+      <node concept="2BbKIm" id="47xL5G3jc4Z" role="1FkZN_">
+        <property role="TrG5h" value="z" />
+      </node>
+      <node concept="1FkZNY" id="47xL5G3jc50" role="1FkZNV">
+        <node concept="3TPQf" id="47xL5G3jc51" role="1FkZNT">
+          <node concept="1DVIoH" id="47xL5G3jc52" role="3TPQ0">
+            <property role="TrG5h" value="mempty" />
+          </node>
+          <node concept="aFS0r" id="47xL5G3jc53" role="3TPQk">
+            <ref role="aFS0e" node="47xL5G3jc4Z" resolve="z" />
+          </node>
+        </node>
+      </node>
+      <node concept="1FkZNY" id="47xL5G3jc54" role="1FkZNV">
+        <node concept="3TPQf" id="47xL5G3jc55" role="1FkZNT">
+          <node concept="1DVIoH" id="47xL5G3jc56" role="3TPQ0">
+            <property role="TrG5h" value="mappend" />
+          </node>
+          <node concept="1jz_ff" id="47xL5G3jc57" role="3TPQk">
+            <node concept="aFS0r" id="47xL5G3jc58" role="1jz_fp">
+              <ref role="aFS0e" node="47xL5G3jc4Z" resolve="z" />
+            </node>
+            <node concept="1jz_ff" id="47xL5G3jc59" role="1jz_f_">
+              <node concept="aFS0r" id="47xL5G3jc5a" role="1jz_f_">
+                <ref role="aFS0e" node="47xL5G3jc4Z" resolve="z" />
+              </node>
+              <node concept="aFS0r" id="47xL5G3jc5b" role="1jz_fp">
+                <ref role="aFS0e" node="47xL5G3jc4Z" resolve="z" />
+              </node>
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
+    <node concept="1FkZNw" id="47xL5G3jc5E" role="1DVIru">
+      <ref role="1FkZWm" node="47xL5G3jc4Y" resolve="Monoid3" />
+      <node concept="1FkZNI" id="47xL5G3jc5F" role="1FkZNz">
+        <ref role="1FkZND" node="2O9ahh6x9Cq" resolve="mappend" />
+        <node concept="1DVIrU" id="47xL5G3jc5G" role="1FkZNF">
+          <node concept="1DVIrB" id="47xL5G3jc5H" role="1DVIr_">
+            <node concept="1DVIoH" id="47xL5G3jc5I" role="1DVIrA">
+              <property role="TrG5h" value="a" />
+            </node>
+          </node>
+          <node concept="1DVIrU" id="47xL5G3jc5J" role="1DVIrw">
+            <node concept="1DVIrB" id="47xL5G3jc5K" role="1DVIr_">
+              <node concept="1DVIoH" id="47xL5G3jc5L" role="1DVIrA">
+                <property role="TrG5h" value="b" />
+              </node>
+            </node>
+            <node concept="1DVIrH" id="47xL5G3jc5M" role="1DVIrw">
+              <node concept="1DVIo5" id="47xL5G3jc5N" role="1DVIrk">
+                <node concept="t0$VC" id="47xL5G3jc5O" role="1DVIo8">
+                  <ref role="t0$VJ" node="47xL5G3jc5L" resolve="b" />
+                </node>
+                <node concept="1DVIo5" id="47xL5G3jc5P" role="1DVIo4">
+                  <node concept="t0$VC" id="47xL5G3jc5Q" role="1DVIo8">
+                    <ref role="t0$VJ" node="47xL5G3jc5I" resolve="a" />
+                  </node>
+                  <node concept="t0$VC" id="47xL5G3jc5R" role="1DVIo4">
+                    <ref role="t0$VJ" node="47xL5G3jc5T" resolve="and" />
+                  </node>
+                </node>
+              </node>
+              <node concept="1DVIrG" id="47xL5G3jc5S" role="1DVIrE">
+                <node concept="1DVIoH" id="47xL5G3jc5T" role="1DVIrJ">
+                  <property role="TrG5h" value="and" />
+                </node>
+                <node concept="1DVIrU" id="47xL5G3jc5U" role="1DVIrD">
+                  <node concept="1DVIrB" id="47xL5G3jc5V" role="1DVIr_">
+                    <node concept="1DVIoH" id="47xL5G3jc5W" role="1DVIrA">
+                      <property role="TrG5h" value="a" />
+                    </node>
+                  </node>
+                  <node concept="1DVIrU" id="47xL5G3jc5X" role="1DVIrw">
+                    <node concept="1DVIrB" id="47xL5G3jc5Y" role="1DVIr_">
+                      <node concept="1DVIoH" id="47xL5G3jc5Z" role="1DVIrA">
+                        <property role="TrG5h" value="b" />
+                      </node>
+                    </node>
+                    <node concept="FlqVS" id="47xL5G3jc60" role="1DVIrw">
+                      <node concept="t0$VC" id="47xL5G3jc61" role="FlqVt">
+                        <ref role="t0$VJ" node="47xL5G3jc5W" resolve="a" />
+                      </node>
+                      <node concept="t0$VC" id="47xL5G3jc62" role="FlqVr">
+                        <ref role="t0$VJ" node="47xL5G3jc5Z" resolve="b" />
+                      </node>
+                      <node concept="t0$VC" id="47xL5G3jc63" role="FlqVm">
+                        <ref role="t0$VJ" node="47xL5G3jc5W" resolve="a" />
+                      </node>
+                    </node>
+                  </node>
+                </node>
+              </node>
+            </node>
+          </node>
+        </node>
+      </node>
+      <node concept="1FkZNI" id="47xL5G3jc64" role="1FkZNz">
+        <ref role="1FkZND" node="2O9ahh6x9CE" resolve="mempty" />
+        <node concept="3P8L2H" id="47xL5G3jc65" role="1FkZNF" />
+      </node>
+      <node concept="3JbUGG" id="47xL5G3jc66" role="1FkZNx">
+        <node concept="3P8Jbz" id="47xL5G3jc67" role="3JbKvY" />
+      </node>
+    </node>
+    <node concept="1DVJbV" id="47xL5G3jiba" role="1DVIru">
+      <node concept="1DVIrG" id="47xL5G3jibb" role="j9CMd">
+        <node concept="1DVIrU" id="47xL5G3jibc" role="1DVIrD">
+          <node concept="1DVIrB" id="47xL5G3jibd" role="1DVIr_">
+            <node concept="1DVIoH" id="47xL5G3jibe" role="1DVIrA">
+              <property role="TrG5h" value="x" />
+            </node>
+          </node>
+          <node concept="1DVIrU" id="47xL5G3jibf" role="1DVIrw">
+            <node concept="1DVIrB" id="47xL5G3jibg" role="1DVIr_">
+              <node concept="3TPQf" id="47xL5G3jibh" role="1DVIrA">
+                <node concept="1DVIoH" id="47xL5G3jibi" role="3TPQ0">
+                  <property role="TrG5h" value="g" />
+                </node>
+                <node concept="3JbUGG" id="47xL5G3jibj" role="3TPQk">
+                  <node concept="1FkZV4" id="47xL5G3jibk" role="1FkZ4g">
+                    <ref role="1FvTW1" node="47xL5G3jibr" resolve="c" />
+                    <ref role="1FkZV7" node="47tET_Wha9b" resolve="C1" />
+                  </node>
+                  <node concept="1jz_ff" id="47xL5G3jibl" role="3JbKvY">
+                    <node concept="3EVAj" id="47xL5G3jibm" role="1jz_f_">
+                      <node concept="aFS0r" id="47xL5G3jibn" role="3EVAi">
+                        <ref role="aFS0e" node="47xL5G3jibq" resolve="b" />
+                      </node>
+                      <node concept="aFS0r" id="47xL5G3jibo" role="3EVAk">
+                        <ref role="aFS0e" node="47xL5G3jibr" resolve="c" />
+                      </node>
+                    </node>
+                    <node concept="aFS0r" id="47xL5G3jibp" role="1jz_fp">
+                      <ref role="aFS0e" node="47xL5G3jibq" resolve="b" />
+                    </node>
+                  </node>
+                  <node concept="2BbKIm" id="47xL5G3jibq" role="5lUUh">
+                    <property role="TrG5h" value="b" />
+                  </node>
+                  <node concept="2BbKIm" id="47xL5G3jibr" role="5lUUh">
+                    <property role="TrG5h" value="c" />
+                  </node>
+                </node>
+              </node>
+            </node>
+            <node concept="3EUms" id="47xL5G3jibs" role="1DVIrw">
+              <node concept="1DVIo5" id="47xL5G3jibt" role="3EUmv">
+                <node concept="3P8L2H" id="47xL5G3jibu" role="1DVIo8" />
+                <node concept="3TPRf" id="47xL5G3jibv" role="1DVIo4">
+                  <node concept="t0$VC" id="47xL5G3jibw" role="3TPR0">
+                    <ref role="t0$VJ" node="47xL5G3jibh" resolve="g" />
+                  </node>
+                  <node concept="3JbUGG" id="47xL5G3jibx" role="3TPQk">
+                    <node concept="1jz_ff" id="47xL5G3jiby" role="3JbKvY">
+                      <node concept="aFS0r" id="47xL5G3jibz" role="1jz_fp">
+                        <ref role="aFS0e" node="47xL5G3jibB" resolve="d" />
+                      </node>
+                      <node concept="3EVAj" id="47xL5G3jib$" role="1jz_f_">
+                        <node concept="aFS0r" id="47xL5G3jib_" role="3EVAi">
+                          <ref role="aFS0e" node="47xL5G3jibB" resolve="d" />
+                        </node>
+                        <node concept="aFS0r" id="47xL5G3jibA" role="3EVAk">
+                          <ref role="aFS0e" node="47xL5G3jic6" resolve="a" />
+                        </node>
+                      </node>
+                    </node>
+                    <node concept="2BbKIm" id="47xL5G3jibB" role="5lUUh">
+                      <property role="TrG5h" value="d" />
+                    </node>
+                  </node>
+                  <node concept="1U20sH" id="47xL5G3jibC" role="lGtFl">
+                    <property role="1U20sK" value="error" />
+                  </node>
+                </node>
+              </node>
+              <node concept="1DVIo5" id="47xL5G3jibD" role="3EUmh">
+                <node concept="t0$VC" id="47xL5G3jibE" role="1DVIo4">
+                  <ref role="t0$VJ" node="47xL5G3jibh" resolve="g" />
+                </node>
+                <node concept="3EUms" id="47xL5G3jibF" role="1DVIo8">
+                  <node concept="3P8MHP" id="47xL5G3jibG" role="3EUmv" />
+                  <node concept="3P8MHP" id="47xL5G3jibH" role="3EUmh" />
+                </node>
+              </node>
+            </node>
+          </node>
+        </node>
+        <node concept="3TPQf" id="47xL5G3jibI" role="1DVIrJ">
+          <node concept="1DVIoH" id="47xL5G3jibJ" role="3TPQ0">
+            <property role="TrG5h" value="qq_lb4_bad" />
+          </node>
+          <node concept="3JbUGG" id="47xL5G3jibK" role="3TPQk">
+            <node concept="1jz_ff" id="47xL5G3jibL" role="3JbKvY">
+              <node concept="aFS0r" id="47xL5G3jibM" role="1jz_fp">
+                <ref role="aFS0e" node="47xL5G3jic6" resolve="a" />
+              </node>
+              <node concept="1jz_ff" id="47xL5G3jibN" role="1jz_f_">
+                <node concept="3EVAj" id="47xL5G3jibO" role="1jz_f_">
+                  <node concept="3EVAj" id="47xL5G3jibP" role="3EVAk">
+                    <node concept="aFS0r" id="47xL5G3jibQ" role="3EVAk">
+                      <ref role="aFS0e" node="47xL5G3jic6" resolve="a" />
+                    </node>
+                    <node concept="3P8Jbz" id="47xL5G3jibR" role="3EVAi" />
+                  </node>
+                  <node concept="3EVAj" id="47xL5G3jibS" role="3EVAi">
+                    <node concept="aFS0r" id="47xL5G3jibT" role="3EVAk">
+                      <ref role="aFS0e" node="47xL5G3jic6" resolve="a" />
+                    </node>
+                    <node concept="3EVAj" id="47xL5G3jibU" role="3EVAi">
+                      <node concept="3P8Jbz" id="47xL5G3jibV" role="3EVAk" />
+                      <node concept="3P8Jbz" id="47xL5G3jibW" role="3EVAi" />
+                    </node>
+                  </node>
+                </node>
+                <node concept="3JbUGG" id="47xL5G3jibX" role="1jz_fp">
+                  <node concept="1FkZV4" id="47xL5G3jibY" role="1FkZ4g">
+                    <ref role="1FkZV7" node="47tET_Wha9b" resolve="C1" />
+                    <ref role="1FvTW1" node="47xL5G3jic0" resolve="c" />
+                  </node>
+                  <node concept="2BbKIm" id="47xL5G3jibZ" role="5lUUh">
+                    <property role="TrG5h" value="b" />
+                  </node>
+                  <node concept="2BbKIm" id="47xL5G3jic0" role="5lUUh">
+                    <property role="TrG5h" value="c" />
+                  </node>
+                  <node concept="1jz_ff" id="47xL5G3jic1" role="3JbKvY">
+                    <node concept="aFS0r" id="47xL5G3jic2" role="1jz_fp">
+                      <ref role="aFS0e" node="47xL5G3jibZ" resolve="b" />
+                    </node>
+                    <node concept="3EVAj" id="47xL5G3jic3" role="1jz_f_">
+                      <node concept="aFS0r" id="47xL5G3jic4" role="3EVAi">
+                        <ref role="aFS0e" node="47xL5G3jibZ" resolve="b" />
+                      </node>
+                      <node concept="aFS0r" id="47xL5G3jic5" role="3EVAk">
+                        <ref role="aFS0e" node="47xL5G3jic0" resolve="c" />
+                      </node>
+                    </node>
+                  </node>
+                </node>
+              </node>
+            </node>
+            <node concept="2BbKIm" id="47xL5G3jic6" role="5lUUh">
+              <property role="TrG5h" value="a" />
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
+    <node concept="1X3_iC" id="47xL5G3jiPv" role="lGtFl">
+      <property role="3V$3am" value="clause" />
+      <property role="3V$3ak" value="af858d84-85f2-42f4-a854-0b3c6b5cd482/8739282858702982568/8739282858702982571" />
+      <node concept="1DVJbV" id="47xL5G3jiy5" role="8Wnug">
+        <node concept="1DVIrG" id="47xL5G3jiy7" role="j9CMd">
+          <node concept="1DVIoH" id="47xL5G3jiy9" role="1DVIrJ">
+            <property role="TrG5h" value="dummy" />
+          </node>
+          <node concept="1DVIrH" id="47xL5G3jiEQ" role="1DVIrD">
+            <node concept="1DVIo5" id="47xL5G3jiJl" role="1DVIrk">
+              <node concept="t0$VC" id="47xL5G3jiF8" role="1DVIo4">
+                <ref role="t0$VJ" node="47xL5G3jiEV" resolve="fdummy" />
+              </node>
+              <node concept="3EUms" id="47xL5G3ji$d" role="1DVIo8">
+                <node concept="3P8MHP" id="47xL5G3ji$f" role="3EUmv" />
+                <node concept="3P8MHP" id="47xL5G3ji$h" role="3EUmh" />
+              </node>
+            </node>
+            <node concept="1DVIrG" id="47xL5G3jiEU" role="1DVIrE">
+              <node concept="1DVIoH" id="47xL5G3jiEV" role="1DVIrJ">
+                <property role="TrG5h" value="fdummy" />
+              </node>
+              <node concept="1DVIrU" id="47xL5G3ji$7" role="1DVIrD">
+                <node concept="1DVIrB" id="47xL5G3ji$8" role="1DVIr_">
+                  <node concept="1DVIoH" id="47xL5G3ji$9" role="1DVIrA">
+                    <property role="TrG5h" value="x" />
+                  </node>
+                </node>
+                <node concept="t0$VC" id="47xL5G3jiF6" role="1DVIrw">
+                  <ref role="t0$VJ" node="47xL5G3ji$9" resolve="x" />
+                </node>
+              </node>
+            </node>
+          </node>
+        </node>
+      </node>
+    </node>
+    <node concept="1DVJbV" id="47xL5G3jc3J" role="1DVIru">
+      <node concept="1DVIrG" id="47xL5G3jc3K" role="j9CMd">
+        <node concept="1DVIoH" id="47xL5G3jc3L" role="1DVIrJ">
+          <property role="TrG5h" value="ii1_bad" />
+        </node>
+        <node concept="1DVIo5" id="47xL5G3jc3M" role="1DVIrD">
+          <node concept="1DVIo5" id="47xL5G3jc3N" role="1DVIo4">
+            <node concept="t0$VC" id="47xL5G3jcaD" role="1DVIo4">
+              <ref role="t0$VJ" node="47xL5G3jc55" resolve="mappend" />
+            </node>
+            <node concept="3EUms" id="47xL5G3jc3P" role="1DVIo8">
+              <node concept="3P8L2H" id="47xL5G3jc3Q" role="3EUmv" />
+              <node concept="3P8L2H" id="47xL5G3jc3R" role="3EUmh" />
+            </node>
+            <node concept="1U20sH" id="47xL5G3jc3S" role="lGtFl">
+              <property role="1U20sK" value="error" />
+            </node>
+          </node>
+          <node concept="3EUms" id="47xL5G3jc3T" role="1DVIo8">
+            <node concept="3P8L2H" id="47xL5G3jc3U" role="3EUmv" />
+            <node concept="3P8L2H" id="47xL5G3jc3V" role="3EUmh" />
+          </node>
+        </node>
+      </node>
+    </node>
+  </node>
 </model>
 
diff --git a/samples/lambdacalc/solutions/samples.lambdacalc.demo/models/samples.lambdacalc.demo@tests.mps b/samples/lambdacalc/solutions/samples.lambdacalc.demo/models/samples.lambdacalc.demo@tests.mps
index 2c2ef7c7..9fba8e2b 100644
--- a/samples/lambdacalc/solutions/samples.lambdacalc.demo/models/samples.lambdacalc.demo@tests.mps
+++ b/samples/lambdacalc/solutions/samples.lambdacalc.demo/models/samples.lambdacalc.demo@tests.mps
@@ -69,12 +69,6 @@
       <concept id="1178549954367" name="jetbrains.mps.baseLanguage.structure.IVisible" flags="ng" index="1B3ioH">
         <child id="1178549979242" name="visibility" index="1B3o_S" />
       </concept>
-      <concept id="6329021646629104957" name="jetbrains.mps.baseLanguage.structure.TextCommentPart" flags="nn" index="3SKdUq">
-        <property id="6329021646629104958" name="text" index="3SKdUp" />
-      </concept>
-      <concept id="6329021646629104954" name="jetbrains.mps.baseLanguage.structure.SingleLineComment" flags="nn" index="3SKdUt">
-        <child id="6329021646629175155" name="commentPart" index="3SKWNk" />
-      </concept>
       <concept id="1146644623116" name="jetbrains.mps.baseLanguage.structure.PrivateVisibility" flags="nn" index="3Tm6S6" />
     </language>
     <language id="63650c59-16c8-498a-99c8-005c7ee9515d" name="jetbrains.mps.lang.access">
@@ -132,19 +126,9 @@
       </concept>
     </language>
     <language id="ceab5195-25ea-4f22-9b92-103b95ca8c0c" name="jetbrains.mps.lang.core">
-      <concept id="1133920641626" name="jetbrains.mps.lang.core.structure.BaseConcept" flags="ng" index="2VYdi">
-        <child id="5169995583184591170" name="smodelAttribute" index="lGtFl" />
-      </concept>
       <concept id="1169194658468" name="jetbrains.mps.lang.core.structure.INamedConcept" flags="ng" index="TrEIO">
         <property id="1169194664001" name="name" index="TrG5h" />
       </concept>
-      <concept id="709746936026466394" name="jetbrains.mps.lang.core.structure.ChildAttribute" flags="ng" index="3VBwX9">
-        <property id="709746936026609031" name="linkId" index="3V$3ak" />
-        <property id="709746936026609029" name="role_DebugInfo" index="3V$3am" />
-      </concept>
-      <concept id="4452961908202556907" name="jetbrains.mps.lang.core.structure.BaseCommentAttribute" flags="ng" index="1X3_iC">
-        <child id="3078666699043039389" name="commentedNode" index="8Wnug" />
-      </concept>
     </language>
   </registry>
   <node concept="2XOHcx" id="6EwjVjWuXZY">
@@ -394,41 +378,32 @@
       <property role="TrG5h" value="DemoScopes" />
       <node concept="3cqZAl" id="1IKbs5XIs8H" role="3clF45" />
       <node concept="3clFbS" id="1IKbs5XIs8L" role="3clF47">
-        <node concept="3SKdUt" id="2tst4bvYo3Z" role="3cqZAp">
-          <node concept="3SKdUq" id="2tst4bvYo41" role="3SKWNk">
-            <property role="3SKdUp" value="FIXME test temporarily disabled" />
-          </node>
-        </node>
-        <node concept="1X3_iC" id="2tst4bvYo2M" role="lGtFl">
-          <property role="3V$3am" value="statement" />
-          <property role="3V$3ak" value="f3061a53-9226-4cc5-a443-f952ceaf5816/1068580123136/1068581517665" />
-          <node concept="2Hmddi" id="RcyXiSVPlH" role="8Wnug">
-            <node concept="2OqwBi" id="RcyXiSVPlI" role="2Hmdds">
-              <node concept="2OqwBi" id="RcyXiSVPlJ" role="2Oq$k0">
-                <node concept="2YIFZM" id="RcyXiSVPlK" role="2Oq$k0">
-                  <ref role="1Pybhc" to="tj24:1N_0WA5JxZO" resolve="TestLaunchTypechecking" />
-                  <ref role="37wK5l" to="tj24:27bTNFfaOo$" resolve="ofNode" />
-                  <node concept="2OqwBi" id="RcyXiSVPlL" role="37wK5m">
-                    <node concept="2WthIp" id="RcyXiSVPlM" role="2Oq$k0" />
-                    <node concept="2XshWL" id="RcyXiSVPlN" role="2OqNvi">
-                      <ref role="2WH_rO" node="35YJGAJTxCf" resolve="resolve" />
-                      <node concept="2tJFMh" id="RcyXiSVPlO" role="2XxRq1">
-                        <node concept="ZC_QK" id="RcyXiSVPvg" role="2tJFKM">
-                          <ref role="2aWVGs" to="ysck:JqEP$8t9fh" resolve="DemoScopes" />
-                        </node>
+        <node concept="2Hmddi" id="RcyXiSVPlH" role="3cqZAp">
+          <node concept="2OqwBi" id="RcyXiSVPlI" role="2Hmdds">
+            <node concept="2OqwBi" id="RcyXiSVPlJ" role="2Oq$k0">
+              <node concept="2YIFZM" id="RcyXiSVPlK" role="2Oq$k0">
+                <ref role="1Pybhc" to="tj24:1N_0WA5JxZO" resolve="TestLaunchTypechecking" />
+                <ref role="37wK5l" to="tj24:27bTNFfaOo$" resolve="ofNode" />
+                <node concept="2OqwBi" id="RcyXiSVPlL" role="37wK5m">
+                  <node concept="2WthIp" id="RcyXiSVPlM" role="2Oq$k0" />
+                  <node concept="2XshWL" id="RcyXiSVPlN" role="2OqNvi">
+                    <ref role="2WH_rO" node="35YJGAJTxCf" resolve="resolve" />
+                    <node concept="2tJFMh" id="RcyXiSVPlO" role="2XxRq1">
+                      <node concept="ZC_QK" id="RcyXiSVPvg" role="2tJFKM">
+                        <ref role="2aWVGs" to="ysck:JqEP$8t9fh" resolve="DemoScopes" />
                       </node>
                     </node>
                   </node>
-                  <node concept="1jxXqW" id="RcyXiSVPlQ" role="37wK5m" />
-                </node>
-                <node concept="liA8E" id="RcyXiSVPlR" role="2OqNvi">
-                  <ref role="37wK5l" to="tj24:27bTNFfaVLW" resolve="skipLocal" />
                 </node>
+                <node concept="1jxXqW" id="RcyXiSVPlQ" role="37wK5m" />
               </node>
-              <node concept="liA8E" id="RcyXiSVPlS" role="2OqNvi">
-                <ref role="37wK5l" to="tj24:27bTNFfaYS2" resolve="checkTypes" />
+              <node concept="liA8E" id="RcyXiSVPlR" role="2OqNvi">
+                <ref role="37wK5l" to="tj24:27bTNFfaVLW" resolve="skipLocal" />
               </node>
             </node>
+            <node concept="liA8E" id="RcyXiSVPlS" role="2OqNvi">
+              <ref role="37wK5l" to="tj24:27bTNFfaYS2" resolve="checkTypes" />
+            </node>
           </node>
         </node>
       </node>