anchor.diff:  //This one is for use as a functor body
   functorBodyExpression
       : implicationExpression 
  -      ( assignmentOp ( (functorStart) => functor | functorBodyExpression ) )?
  +      ( assignmentOp ( (assignableFunctorStart) => assignableFunctor | functorBodyExpression ) )?
       ;
       
   assignmentOp
  
positive.code:     ;
  
  userAnnotation 
      : annotationName ( arguments | literal )?
      ;
  
  typeName
  
negative.code: 
  stringLiteral
      : SIMPLESTRINGLITERAL
      | LEFTSTRINGLITERAL expression (MIDDLESTRINGLITERAL expression)* RIGHTSTRINGLITERAL 
      ;
  
  assignable 
      : (assignableFunctorStart) => assignableFunctor
      | expression
      ;
  
  //This one is fully general
  