2.


%{
#include<stdio.h>
int yylex(void);
void yyerror (char *);

}%

%token INTEGER
%left '+ '-'
%left '* '/'

%%
program:
program expr '\n' {printf(%d\n",$a2);}
|
;
expr:
INTEGER{$$=$1;)
| expr '+'expr{$$=$1+$3;)}
| expr '-'expr{$$=$1-$3;)}
| expr '*'expr{$$=$1*$3;)}
| expr '\'expr{if ($3==0){yyerror("Getting zero");}
;
%%
void yyerror (char *s)
{
fprintf(student,"s\n",s);
}