Expressions: for IfThen, algebralize only the then- and else-part #237

include/mp/flat/constr_2_expr.h

@@ -387,14 +387,23 @@ class Constraints2Expr {
     return false;
   }
 
-  /// Handle logical expression in an algebraic con
+  /// Handle logical expressions in an algebraic con
   /// @return whether to remove the original \a con.
   template <class Con>
   bool HandleLogicalArgs(const Con& con, int ) {
     VisitArguments(con, MarkVarIfLogical_);          // Mark as proper vars
     return false;                                    // don't remove immediately
   }
 
+  /// Handle logical expressions in an IfThen
+  /// @return whether to remove the original \a con.
+  template <>
+  bool HandleLogicalArgs(const IfThenConstraint& con, int ) {
+    MarkVarIfLogical_(con.GetArguments()[1]);    // then part
+    MarkVarIfLogical_(con.GetArguments()[2]);    // else part
+    return false;
+  }
+
   /// Special linear cases.
   /// Not doing any more because these simplifications
   /// interfere with result variable marking.

include/mp/flat/constr_keeper.h

@@ -158,8 +158,8 @@ class ConstraintKeeper final
     return false;
   }
 
-  /// Mark whether we could result vars of functional constraints
-  /// as vars, vs using these constraints as expressions
+  /// Mark whether we could use result vars of functional constraints
+  /// as expressions
   void MarkExprResultVars(BasicFlatConverter& cvt) override {
     assert(&cvt == &GetConverter());         // Using the same Converter
     DoMarkForResultVars();

test/end2end/cases/categorized/fast/logical/modellist.json

@@ -45,7 +45,9 @@
     "name" : "ifthen_var cmp:eps=0 chk:fail",
     "tags" : ["logical"],
     "options": {
-      "ANYSOLVER_options": "cvt:cmp:eps=0 chk:fail"
+      "ANYSOLVER_options": "cvt:cmp:eps=0 chk:fail",
+      "mp2nl_options": "solver_options='cvt:cmp:eps=0 chk:fail'"
+
     },
     "values": {
       "solve_result_num": 150