anchor.diff:          |  AMPERAMPERAMPER  nterm<<V>>
           |  BAR  nterm<<V>>
           |  BARBAR  nterm<<V>>
  -        |  MATCHES
  +        |  TOKMATCHES
               ( dot_field_selection
               | LBRACE dot_field_item (COMMA dot_field_item)* RBRACE
               | VAR
  
positive.code:         LPAREN [ assign_value (COMMA assign_value)* ] RPAREN
  
      rule function_declaration:
          FUNCTION
          [
              ( Type_sitem
              | LPAREN Type_nitem RPAREN
  
negative.code:     token TOKRESET_BY: "reset_by"
      token TOKRESULT: "result"
      token TOKRETURN: "return"
      token TOKRULE: "rule"
      token TOKRULES: "rules"
      token TOKSB: "SB"
      token TOKSBR: "SBR"
      token TOKSCHEDULE: "schedule"
      token TOKSEQ: "seq"
      token TOKSET: "set"
      token TOKSTRING: "String"
      token TOKSTRUCT: "struct"
      token TOKTAGGED: "tagged"
      token TOKTTYPE: "Type"
      token TOKTYPE: "type"
      token TOKTYPECLASS: "typeclass"
      token TOKTYPEDEF: "typedef"
      token TOKUNION: "union"
      token TOKWHILE: "while"
  
  