anchor.diff:      //TODO (jln): This does not take library prefix into account.
       foreach(targetIdent).update((AbstractType alpha) {
         TypeIdentifier alphaPropertyIdent = new PropertyTypeIdentifier(alpha, new Name.FromIdentifier(n.propertyName));
  -      _subsetConstraint(alphaPropertyIdent, nodeIdent);
  +      subsetConstraint(alphaPropertyIdent, nodeIdent);
       });
     }
     
  
positive.code:     if (ident != n){
        //TODO (jln): A possible speedup would be changing the simpleidentifiers to the identifier used in the variable decl.
        // This can be done in a previous AST-gothrough
        _equalConstraint(new ExpressionTypeIdentifier(ident), new ExpressionTypeIdentifier(n));
      }
    }
    
  
negative.code:     //TODO (jln): This does not take library prefix into account.
      foreach(prefixIdent).update((AbstractType alpha) {
        TypeIdentifier alphaPropertyIdent = new PropertyTypeIdentifier(alpha, new Name.FromIdentifier(n.identifier));
        subsetConstraint(alphaPropertyIdent, nodeIdent);
      });
    }
    
  