简化文法.txt

1. <pro>→<mainkey>(){<des><sts>}

2. <des>→<ses><des>|<null>

3. <ses>→<intkey><idt>;

4. (1)<idt>→<id><idts>

 (2)<idts>→,<idt>|null

5. <sts>→<sent><sts>|null

6. <sent>→<ifs>|<whiles>|<fors>|<scanfs>|<printfs>

|<coms>|<asst>

7.(1) <ifs>→<ifkey> (<exp>)<coms><elses>

(2)<elses>→<eleskey><coms>|null

8. <whiles>→<whilekey> (<exp>)<coms>;

9. <fors>→<forkey> (<exp>;<exp>;<exp>) <coms>;

10. <coms>→{<sts>}

11. <asst>→<exp>;

12. (1)<exp>→<id><exps>
	(2)<exps>→=<arit>|<rel>

13. (1)<rel>→<opt><relop><arit>|null
	(2)<opt>→+<arit>|-<arit>|*<term>|/<term>|null

14. (1)<relop>→><eq>|<<eq>|=<eq>|!<eq>
	(2)<eq>→=|null

15. (1)<arit>→<term><oparit>
    (2)<oparit>→+<arit>|-<arit>|null

16. (1)<term>→<factor><opterm>
	(2)<opterm>→*<term>|/<term>|null

17. <factor>→<id>|<unint>|(<arit>)

18.(1)<id>→<idh><idta>
(2)<idh>→<letter>
(3)<idta>→<letter><idta>|<num><idta>|<null>

19. <unint>→<num><unint>|<null>

20. <letter>→a|b|…|z|A|B|…|Z

21. <num>→0|1|2|3|4|5|6|7|8|9

22. <mainkey>→main

23. <ifkey>→if

24. <eleskey>→else

25. <whilekey>→while

26. <forkey>→for

27. <intkey>→int

28. <scanfs>→<scanfkey>(id);

29. <printfkey>→<printfkey>(id);