anchor.diff:              | variable_declaration_or_call SEMICOLON
               )*
               TOKENDRULES [ COLON  VAR]
  -        | FUNCTION function_argument
  +        | TOKFUNCTION function_argument
           | function_operator [expr<<[]>>]
           | expr<<[]>> ( LEQ expr<<[]>> )* [expr<<[]>>]
           | QUESTION
  
positive.code:     token TYPEVAR: " "
      token CLASSVAR: " "
  
      token BEGIN: "begin"
      token TOKENDACTIONVALUE: "endactionvalue"
      token TOKENDACTION: "endaction"
      token TOKENDCASE: "endcase"
      token TOKENDFUNCTION: "endfunction"
      token TOKENDINSTANCE: "endinstance"
  
negative.code:         TOKRETURN assign_value SEMICOLON
  
      rule group_statement:
          TOKBEGIN
          statement_list
          TOKEND
  
      rule seq_statement:
          TOKSEQ
  