anchor.diff:            tok.setText("Entry");
             bt.setIdentifier( new Identifier(tok) ); }
           (
  -          ut2=unionType
  +          ut2=abbreviatedType
             { tal.addType($ut2.type);
               bt.setEndToken(null); }
           | { displayRecognitionError(getTokenNames(), 
  
positive.code:           i=INTERSECTION_OP
            { it.setEndToken($i); }
            (
              at2=abbreviatedType
              { it.addStaticType($at2.type);
                it.setEndToken(null); }
            | { displayRecognitionError(getTokenNames(), 
  
negative.code:     ;
      
  type returns [StaticType type]
      : unionType 
        { $type=$unionType.type; }
      ;
      
  entryType returns [StaticType type]
      @init { BaseType bt=null; 
              TypeArgumentList tal=null; }
      : ut1=abbreviatedType
        { $type=$ut1.type; 
          bt = new BaseType(null); 
          tal = new TypeArgumentList(null); 
  