/* File: ch3-01.y   (modified from lex & yacc book by John Levine) */
%{
#include <stdio.h>
%}

%token NAME NUMBER
%%
statement:  NAME '=' expression
    |   expression                  { printf("= %d\n", $1); }
    ;

expression: expression '+' NUMBER   { $$ = $1 + $3; }
    |   expression '-' NUMBER       { $$ = $1 - $3; }
    |   NUMBER                      { $$ = $1; }
    ;

%%

main() {
   yyparse() ;
}