==================================
Expressions
==================================

1 + 2 * 3;
4 * 5 + 6;
7 * (8 + 9);

---

(program
  (statement (sum
    (number)
    (product (number) (number))))
  (statement (sum
    (product (number) (number))
    (number)))
  (statement (product
    (number)
    (parenthesized_expression (sum (number) (number))))))
