output.txt

编译原理程序设计 写的很好哦 很有参考价值

The Grammar of a while sentence:
******************************************
*      (1)      S --> while(A) B         *
*      (2)      A --> N rop N            *
*      (3)      B --> N = N op N         *
*      (4)      N --> id                 *
******************************************
The while sentence is:
while(a rop b c = d op esd

Your input does not tally with the grammar!