bugfix: be careful with scope, yacc couldn't see the operator precedence
bugfix: be careful with scope, yacc couldn't see the operator precedence

resulting in 357 shift/reduce errors.
necozay/tulip-control,necozay/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control,necozay/tulip-control,necozay/tulip-control,tulip-control/tulip-control,necozay/tulip-control