%{

package main

import (
        "fmt"
)

%}

%union
{
  n int
}

%type <n> expr term

%start expr
%%

expr
  : term '+' term
  { 
   fmt.Printf("%d + %d\n", $1, $3)
    $$ = 0
  }
  ;

term: '9' 
  {
    $$ = 9
  }
  ;

%%


type lex struct {
}

func (l *lex) Error(s string) {
	fmt.Println("error", s)
}

func (l *lex) Lex(lval *yySymType) int {
	return 9
}