anchor.diff:      PRIMARY;
       SATISFIES_EXPR;
       SEQ_ARG;
  +    SEQ_TYPE;
  +    SEQ_TYPE_PARAMETER;
       SPECIAL_ARG;
       TRY_CATCH_STMT;
       TRY_RESOURCE;
  
positive.code:     ;
  
  typeArgument
      : type '...'?
      ; /*| '#'! dimension
      ;
  
  
negative.code:     ;
  
  formalParameterType
      : type ( '...' -> ^(SEQ_TYPE type) | -> type )
      | VOID -> VOID
      ;
  
  // Control structures.
  