anchor.diff:        TypeIdentifier nodeIdent = new ExpressionTypeIdentifier(node);
         
         // [exp] \subseteq [v = exp]
  -      _subsetConstraint(exp, nodeIdent);
  +      subsetConstraint(exp, nodeIdent);
       }
     }
     
  
positive.code:    // [exp] \subseteq [v]
    _assignmentSimpleIdentifier(SimpleIdentifier leftHandSide, TypeIdentifier expIdent){
      TypeIdentifier vIdent = new ExpressionTypeIdentifier(leftHandSide);
      _subsetConstraint(expIdent, vIdent);
    }
    
    // v.prop = exp;
  
negative.code:       return source.resolvedIdentifiers[exp].identifier;
      } else
        return exp;
    }
    
    AbstractType _getAbstractType(Name className, LibraryElement library, SourceElement source){
  