可以运行但是输出了类似以下的内容：
r -> . ( bool ) ,and ] [ relfactor -> . id ,and ] [ relunary -> . relfactor ,and ] [ relterm -> . relunary ,and ] [ rel -> . relexpr ,and ] [ equality -> . rel ,and ] [ boolterm -> . equality ,and ] [ equality -> . equality != rel ,or ] [ rel -> . rel < relexpr ,or ] [ rel -> . rel > relexpr ,or ] [ relexpr -> . relexpr + relterm ,or ] [ relterm -> . relterm * relunary ,or ] [ relterm -> . relterm / relunary ,or ] [ relunary -> . - relunary ,or ] [ relfactor -> . id ,or ] [ relfactor -> . num ,or ] [ relunary -> . relfactor ,or ] [ relexpr -> . relterm ,or ] [ rel -> . relexpr ,or ] [ equality -> . rel ,or ] [ equality -> . false ,or ] [ boolterm -> . equality ,or ] [ equality -> . equality == rel ,; ] [ rel -> . rel < relexpr ,== ] [ rel -> . rel <= relexpr ,== ] [ rel -> . rel >= relexpr ,== ] [ rel -> . rel > relexpr ,== ] [ relexpr -> . relexpr + relterm ,== ] [ relexpr -> . relexpr - relterm ,== ] [ join -> joinand . boolterm ,and ] [ relterm -> . relterm * relunary ,== ] [ relterm -> . relterm / relunary ,== ] [ relunary -> . ! relunary ,== ] [ relterm -> . relterm * relunary ,> ] [ relfactor -> . id ,< ] [ rel -> . rel >= relexpr ,!= ] [ relunary -> . - relunary ,> ] [ relunary -> . ! relunary ,* ] [ relunary -> . relfactor ,== ] [ relfactor -> . id ,> ] [ relfactor -> . id ,; ] [ relterm -> . relunary ,+ ] [ rel -> . rel >= relexpr ,or ] [ rel -> . rel >= relexpr ,> ] [ rel -> . rel > relexpr ,>= ] [ relterm -> . relterm * relunary ,+ ] [ relunary -> . ! relunary ,< ] [ relfactor -> . id ,>= ] [ relterm -> . relterm * relunary ,!= ] [ join -> joinand . boolterm ,or ] [ relterm -> . relterm / relunary ,; ] [ relexpr -> . relexpr + relterm ,; ] [ relfactor -> . id ,+ ] [ relunary -> . - relunary ,!= ] [ relunary -> . - relunary ,* ] [ relunary -> . relfactor ,+ ] [ relterm -> . relterm / relunary ,- ] [ relexpr -> . relexpr - relterm ,+ ] [ relexpr -> . relexpr + relterm ,- ] [ rel -> . rel > relexpr ,> ] [ rel -> . rel >= relexpr ,>= ] [ rel -> . rel <= relexpr ,<= ] [ rel -> . rel < relexpr ,< ] [ relexpr -> . relexpr + relterm ,+ ] [ relexpr -> . relexpr - relterm ,- ] [ relterm -> . relterm * relunary ,- ] [ relunary -> . - relunary ,- ] [ relfactor -> . ( bool ) ,- ] [ relterm -> . relterm * relunary ,>= ] [ relfactor -> . ( bool ) ,> ] [ rel -> . rel <= relexpr ,!= ] [ relexpr -> . relterm ,- ] [ relfactor -> . id ,- ] [ relfactor -> . num ,- ] [ equality -> . false ,!= ] [ relterm -> . relunary ,- ] [ relexpr -> . relterm ,!= ] [ relfactor -> . num ,and ] [ relunary -> . - relunary ,; ] [ relunary -> . - relunary ,+ ] [ relunary -> . relfactor ,; ] [ relexpr -> . relexpr - relterm ,> ] [ relterm -> . relunary ,; ] [ equality -> . rel ,; ] [ join -> joinand . boolterm ,; ] [ relunary -> . ! relunary ,/ ] [ relexpr -> . relterm ,+ ] [ relterm -> . relterm / relunary ,/ ] [ relterm -> . relterm * relunary ,* ] [ relfactor -> . id ,/ ] [ relexpr -> . relexpr - relterm ,and ] [ rel -> . relexpr ,!= ] [ rel -> . relexpr ,> ] [ equality -> . true ,or ] [ relexpr -> . relterm ,> ] [ relterm -> . relterm / relunary ,+ ] [ relterm -> . relunary ,< ] [ relunary -> . ! relunary ,or ] [ equality -> . true ,; ] [ relexpr -> . relterm ,>= ] [ relunary -> . - relunary ,>= ] [ rel -> . rel > relexpr ,!= ] [ relunary -> . ! relunary ,- ] [ relterm -> . relunary ,/ ] [ relfactor -> . ( bool ) ,; ] [ relexpr -> . relexpr - relterm ,; ] [ equality -> . equality != rel ,; ] [ rel -> . relexpr ,; ] [ boolterm -> . equality ,; ] [ relterm -> . relterm * relunary ,<= ] [ relunary -> . ! relunary ,; ] [ rel -> . rel <= relexpr ,or ] [ rel -> . relexpr ,>= ] [ relfactor -> . num ,* ] [ relfactor -> . num ,/ ] [ relunary -> . ! relunary ,>= ] [ equality -> . equality == rel ,or ] [ relfactor -> . id ,== ] [ relunary -> . ! relunary ,+ ] [ rel -> . rel <= relexpr ,< ] [ rel -> . rel < relexpr ,<= ] [ equality -> . false ,; ] [ relexpr -> . relterm ,; ] [ rel -> . rel < relexpr ,; ] [ relunary -> . ! relunary ,> ] [ relfactor -> . num ,<= ] [ relunary -> . relfactor ,> ] [ relfactor -> . ( bool ) ,/ ] [ equality -> . equality != rel ,and ] [ relunary -> . relfactor ,- ] [ relterm -> . relunary ,* ] [ rel -> . relexpr ,< ] [ relfactor -> . id ,!= ] [ relexpr -> . relterm ,and ] [ relunary -> . relfactor ,* ] [ relfactor -> . ( bool ) ,* ] [ relterm -> . relunary ,> ] [ relterm -> . relterm / relunary ,< ] [ equality -> . true ,and ] [ relfactor -> . num ,+ ] [ relfactor -> . id ,* ] [ relterm -> . relterm * relunary ,; ] [ rel -> . rel >= relexpr ,; ] [ relfactor -> . ( bool ) ,+ ] [ relunary -> . relfactor ,>= ] [ relfactor -> . num ,>= ] [ relfactor -> . ( bool ) ,>= ] [ relexpr -> . relexpr + relterm ,and ] [ relterm -> . relunary ,>= ] [ relexpr -> . relexpr - relterm ,>= ] [ relexpr -> . relexpr + relterm ,>= ] [ relunary -> . relfactor ,/ ] [ rel -> . rel >= relexpr ,< ] [ rel -> . rel < relexpr ,>= ] [ relfactor -> . ( bool ) ,== ] [ rel -> . rel <= relexpr ,> ] [ rel -> . rel > relexpr ,<= ] [ rel -> . relexpr ,<= ] [ rel -> . rel > relexpr ,; ] [ relunary -> . - relunary ,< ] [ relexpr -> . relterm ,<= ] [ relterm -> . relterm / relunary ,> ] [ relterm -> . relunary ,<= ] [ relterm -> . relterm / relunary ,!= ] [ relunary -> . relfactor ,<= ] [ relfactor -> . id ,<= ] [ relfactor -> . ( bool ) ,<= ] [ relunary -> . - relunary ,<= ] [ relexpr -> . relexpr - relterm ,or ] [ relunary -> . ! relunary ,<= ] [ relterm -> . relterm / relunary ,<= ] [ rel -> . rel >= relexpr ,and ] [ relexpr -> . relexpr + relterm ,> ] [ relterm -> . relterm / relunary ,>= ] [ equality -> . rel ,== ] [ relexpr -> . relexpr - relterm ,<= ] [ relfactor -> . ( bool ) ,< ] [ relexpr -> . relexpr + relterm ,<= ] [ relexpr -> . relterm ,< ] [ relunary -> . relfactor ,< ] [ relfactor -> . num ,< ] [ relfactor -> . num ,> ] [ relterm -> . relterm * relunary ,< ] [ relexpr -> . relexpr - relterm ,< ] [ relexpr -> . relexpr + relterm ,< ] [ rel -> . rel < relexpr ,!= ] [ rel -> . rel <= relexpr ,>= ] [ rel -> . rel >= relexpr ,<= ] [ rel -> . rel <= relexpr ,; ] [ equality -> . true ,!= ] [ relfactor -> . num ,; ] [ relterm -> . relterm * relunary ,/ ] [ relterm -> . relterm / relunary ,* ] [ equality -> . rel ,!= ] [ relterm -> . relunary ,!= ] [ relunary -> . relfactor ,!= ] [ relfactor -> . num ,!= ] [ rel -> . rel < relexpr ,> ] [ rel -> . rel > relexpr ,< ] [ relfactor -> . ( bool ) ,!= ] [ relunary -> . ! relunary ,!= ] [ relfactor -> . ( bool ) ,or ] [ relexpr -> . relexpr + relterm ,!= ] [ relterm -> . relunary ,or ] [ equality -> . equality == rel ,== ] [ equality -> . equality != rel ,!= ] [ equality -> . equality != rel ,== ] [ relexpr -> . relexpr - relterm ,!= ] [ equality -> . equality == rel ,!= ] [ equality -> . false ,== ] [ equality -> . true ,== ] [ rel -> . relexpr ,== ] [ relexpr -> . relterm ,== ]
并且是死循环
可以运行但是输出了类似以下的内容：
r -> . ( bool ) ,and ] [ relfactor -> . id ,and ] [ relunary -> . relfactor ,and ] [ relterm -> . relunary ,and ] [ rel -> . relexpr ,and ] [ equality -> . rel ,and ] [ boolterm -> . equality ,and ] [ equality -> . equality != rel ,or ] [ rel -> . rel < relexpr ,or ] [ rel -> . rel > relexpr ,or ] [ relexpr -> . relexpr + relterm ,or ] [ relterm -> . relterm * relunary ,or ] [ relterm -> . relterm / relunary ,or ] [ relunary -> . - relunary ,or ] [ relfactor -> . id ,or ] [ relfactor -> . num ,or ] [ relunary -> . relfactor ,or ] [ relexpr -> . relterm ,or ] [ rel -> . relexpr ,or ] [ equality -> . rel ,or ] [ equality -> . false ,or ] [ boolterm -> . equality ,or ] [ equality -> . equality == rel ,; ] [ rel -> . rel < relexpr ,== ] [ rel -> . rel <= relexpr ,== ] [ rel -> . rel >= relexpr ,== ] [ rel -> . rel > relexpr ,== ] [ relexpr -> . relexpr + relterm ,== ] [ relexpr -> . relexpr - relterm ,== ] [ join -> joinand . boolterm ,and ] [ relterm -> . relterm * relunary ,== ] [ relterm -> . relterm / relunary ,== ] [ relunary -> . ! relunary ,== ] [ relterm -> . relterm * relunary ,> ] [ relfactor -> . id ,< ] [ rel -> . rel >= relexpr ,!= ] [ relunary -> . - relunary ,> ] [ relunary -> . ! relunary ,* ] [ relunary -> . relfactor ,== ] [ relfactor -> . id ,> ] [ relfactor -> . id ,; ] [ relterm -> . relunary ,+ ] [ rel -> . rel >= relexpr ,or ] [ rel -> . rel >= relexpr ,> ] [ rel -> . rel > relexpr ,>= ] [ relterm -> . relterm * relunary ,+ ] [ relunary -> . ! relunary ,< ] [ relfactor -> . id ,>= ] [ relterm -> . relterm * relunary ,!= ] [ join -> joinand . boolterm ,or ] [ relterm -> . relterm / relunary ,; ] [ relexpr -> . relexpr + relterm ,; ] [ relfactor -> . id ,+ ] [ relunary -> . - relunary ,!= ] [ relunary -> . - relunary ,* ] [ relunary -> . relfactor ,+ ] [ relterm -> . relterm / relunary ,- ] [ relexpr -> . relexpr - relterm ,+ ] [ relexpr -> . relexpr + relterm ,- ] [ rel -> . rel > relexpr ,> ] [ rel -> . rel >= relexpr ,>= ] [ rel -> . rel <= relexpr ,<= ] [ rel -> . rel < relexpr ,< ] [ relexpr -> . relexpr + relterm ,+ ] [ relexpr -> . relexpr - relterm ,- ] [ relterm -> . relterm * relunary ,- ] [ relunary -> . - relunary ,- ] [ relfactor -> . ( bool ) ,- ] [ relterm -> . relterm * relunary ,>= ] [ relfactor -> . ( bool ) ,> ] [ rel -> . rel <= relexpr ,!= ] [ relexpr -> . relterm ,- ] [ relfactor -> . id ,- ] [ relfactor -> . num ,- ] [ equality -> . false ,!= ] [ relterm -> . relunary ,- ] [ relexpr -> . relterm ,!= ] [ relfactor -> . num ,and ] [ relunary -> . - relunary ,; ] [ relunary -> . - relunary ,+ ] [ relunary -> . relfactor ,; ] [ relexpr -> . relexpr - relterm ,> ] [ relterm -> . relunary ,; ] [ equality -> . rel ,; ] [ join -> joinand . boolterm ,; ] [ relunary -> . ! relunary ,/ ] [ relexpr -> . relterm ,+ ] [ relterm -> . relterm / relunary ,/ ] [ relterm -> . relterm * relunary ,* ] [ relfactor -> . id ,/ ] [ relexpr -> . relexpr - relterm ,and ] [ rel -> . relexpr ,!= ] [ rel -> . relexpr ,> ] [ equality -> . true ,or ] [ relexpr -> . relterm ,> ] [ relterm -> . relterm / relunary ,+ ] [ relterm -> . relunary ,< ] [ relunary -> . ! relunary ,or ] [ equality -> . true ,; ] [ relexpr -> . relterm ,>= ] [ relunary -> . - relunary ,>= ] [ rel -> . rel > relexpr ,!= ] [ relunary -> . ! relunary ,- ] [ relterm -> . relunary ,/ ] [ relfactor -> . ( bool ) ,; ] [ relexpr -> . relexpr - relterm ,; ] [ equality -> . equality != rel ,; ] [ rel -> . relexpr ,; ] [ boolterm -> . equality ,; ] [ relterm -> . relterm * relunary ,<= ] [ relunary -> . ! relunary ,; ] [ rel -> . rel <= relexpr ,or ] [ rel -> . relexpr ,>= ] [ relfactor -> . num ,* ] [ relfactor -> . num ,/ ] [ relunary -> . ! relunary ,>= ] [ equality -> . equality == rel ,or ] [ relfactor -> . id ,== ] [ relunary -> . ! relunary ,+ ] [ rel -> . rel <= relexpr ,< ] [ rel -> . rel < relexpr ,<= ] [ equality -> . false ,; ] [ relexpr -> . relterm ,; ] [ rel -> . rel < relexpr ,; ] [ relunary -> . ! relunary ,> ] [ relfactor -> . num ,<= ] [ relunary -> . relfactor ,> ] [ relfactor -> . ( bool ) ,/ ] [ equality -> . equality != rel ,and ] [ relunary -> . relfactor ,- ] [ relterm -> . relunary ,* ] [ rel -> . relexpr ,< ] [ relfactor -> . id ,!= ] [ relexpr -> . relterm ,and ] [ relunary -> . relfactor ,* ] [ relfactor -> . ( bool ) ,* ] [ relterm -> . relunary ,> ] [ relterm -> . relterm / relunary ,< ] [ equality -> . true ,and ] [ relfactor -> . num ,+ ] [ relfactor -> . id ,* ] [ relterm -> . relterm * relunary ,; ] [ rel -> . rel >= relexpr ,; ] [ relfactor -> . ( bool ) ,+ ] [ relunary -> . relfactor ,>= ] [ relfactor -> . num ,>= ] [ relfactor -> . ( bool ) ,>= ] [ relexpr -> . relexpr + relterm ,and ] [ relterm -> . relunary ,>= ] [ relexpr -> . relexpr - relterm ,>= ] [ relexpr -> . relexpr + relterm ,>= ] [ relunary -> . relfactor ,/ ] [ rel -> . rel >= relexpr ,< ] [ rel -> . rel < relexpr ,>= ] [ relfactor -> . ( bool ) ,== ] [ rel -> . rel <= relexpr ,> ] [ rel -> . rel > relexpr ,<= ] [ rel -> . relexpr ,<= ] [ rel -> . rel > relexpr ,; ] [ relunary -> . - relunary ,< ] [ relexpr -> . relterm ,<= ] [ relterm -> . relterm / relunary ,> ] [ relterm -> . relunary ,<= ] [ relterm -> . relterm / relunary ,!= ] [ relunary -> . relfactor ,<= ] [ relfactor -> . id ,<= ] [ relfactor -> . ( bool ) ,<= ] [ relunary -> . - relunary ,<= ] [ relexpr -> . relexpr - relterm ,or ] [ relunary -> . ! relunary ,<= ] [ relterm -> . relterm / relunary ,<= ] [ rel -> . rel >= relexpr ,and ] [ relexpr -> . relexpr + relterm ,> ] [ relterm -> . relterm / relunary ,>= ] [ equality -> . rel ,== ] [ relexpr -> . relexpr - relterm ,<= ] [ relfactor -> . ( bool ) ,< ] [ relexpr -> . relexpr + relterm ,<= ] [ relexpr -> . relterm ,< ] [ relunary -> . relfactor ,< ] [ relfactor -> . num ,< ] [ relfactor -> . num ,> ] [ relterm -> . relterm * relunary ,< ] [ relexpr -> . relexpr - relterm ,< ] [ relexpr -> . relexpr + relterm ,< ] [ rel -> . rel < relexpr ,!= ] [ rel -> . rel <= relexpr ,>= ] [ rel -> . rel >= relexpr ,<= ] [ rel -> . rel <= relexpr ,; ] [ equality -> . true ,!= ] [ relfactor -> . num ,; ] [ relterm -> . relterm * relunary ,/ ] [ relterm -> . relterm / relunary ,* ] [ equality -> . rel ,!= ] [ relterm -> . relunary ,!= ] [ relunary -> . relfactor ,!= ] [ relfactor -> . num ,!= ] [ rel -> . rel < relexpr ,> ] [ rel -> . rel > relexpr ,< ] [ relfactor -> . ( bool ) ,!= ] [ relunary -> . ! relunary ,!= ] [ relfactor -> . ( bool ) ,or ] [ relexpr -> . relexpr + relterm ,!= ] [ relterm -> . relunary ,or ] [ equality -> . equality == rel ,== ] [ equality -> . equality != rel ,!= ] [ equality -> . equality != rel ,== ] [ relexpr -> . relexpr - relterm ,!= ] [ equality -> . equality == rel ,!= ] [ equality -> . false ,== ] [ equality -> . true ,== ] [ rel -> . relexpr ,== ] [ relexpr -> . relterm ,== ]
并且是死循环