anchor.diff:      token TOKC: "C"
       token TOKCASE: "case"
       token TOKCF: "CF"
  -    token TOKCLK: "CLK"
       token TOKCLOCKED_BY: "clocked_by"
       token TOKDEFAULT: "default"
       token TOKDEFAULT_CLOCK: "default_clock"
  
positive.code: 
      rule interface_declaration:
          TOKINTERFACE CLASSVAR*
          #typevar_item_or_var [ VAR ]
          (typevar_item | VAR) [ VAR ]
              ( equal_value
              | [ SEMICOLON ] [ interface_body ] TOKENDINTERFACE [ COLON VAR ]
              )
  
negative.code:     token EQEQ: "=="
      token EQUAL: "="
      token STARSTAR: "**"
      token STAR: "*"
      token TOKNOTEQUAL: "!="
      token TOKEXCLAIM: "!"
  