sample1.y

%{  
#include<stdio.h>  
#include<stdlib.h>  
%}  
%token num alpha LT GT EQ LE GE NE AND OR INC DEC END  
%left '+''-'  
%left '*''/'  
%right '^'  
%right '='  
%nonassoc UMINUS  
%nonassoc IF  
%nonassoc ELSE  
%left GE NE LT GT LE EQ  
%left AND OR  
%%  
S:ST END{printf("\n Accepted");exit(0);}  
ST:IF'('F')''{'ST'}'%prec IF  
|IF'('F')''{'ST'}'ELSE'{'ST'}'  
|E';'  
|E';'ST  
F:C LO C  
|C  
LO:AND  
|OR  
C:E RELOP E  
|E  
E:alpha '='E  
|E'+'E   
|E'-'E   
|E'*'E   
|E'/'E  
|E'^'E  
|'('E')'   
|'-'E %prec UMINUS  
|alpha  
|num  
|alpha INC  
|alpha DEC  
RELOP:LT  
|GT  
|EQ  
|LE  
|GE  
|NE  
;  
%%  
#include"lex.yy.c"  
int main()  
{   
yyparse();  
yylex();  
return END;  
}  
yyerror(char *s)  
{  
printf("\nNot Accepted");  
exit(0);
} 
int yywrap(){return 1;}