public Expr term()
{
Expr x = unary();
while (look.tag == '*' || look.tag == '/')
{
Token tok = look;
move();
x = new Arith(tok, x, unary());
}
return(x);
}
public Expr expr()
{
Expr x = term();
while (look.tag == '+' || look.tag == '-')
{
Token tok = look;
move();
x = new Arith(tok, x, term());
}
return(x);
}