anchor.diff:      ;
   
   specialArgument
  -    : (union | 'local') memberName (containment | specifier)
  +    : (type | 'local') memberName (containment | specifier)
       //| isCondition
       //| existsCondition
       ;
  
positive.code:     ;
  
  variable
      : (union | 'local') memberName formalParameters*
      ;
  
  // Lexer
  
negative.code:     ;
  
  typeConstraint
      : 'given' typeName formalParameters? caseTypes? metatypes? satisfiedTypes? abstractedType?
      -> ^(TYPE_CONSTRAINT typeName formalParameters? satisfiedTypes? abstractedType?)
      ;
      
  typeConstraints
      : typeConstraint+
      -> ^(TYPE_CONSTRAINT_LIST typeConstraint+)
      ;
  
  type
  