==================
unary operator -
==================

foo = -3

---

(config_file 
  (body 
    (attribute 
      (identifier) 
      (expression 
        (operation 
          (unary_operation (expr_term (literal_value (numeric_lit))))))))) 

==================
unary operator !
==================

foo = !true

---

(config_file 
  (body 
    (attribute 
      (identifier) 
        (expression 
          (operation 
            (unary_operation (expr_term (literal_value (bool_lit))))))))) 

==================
binary operators +
==================

foo = 1+2

---

(config_file 
  (body 
    (attribute 
      (identifier) 
        (expression 
          (operation 
            (binary_operation 
              (expr_term (literal_value (numeric_lit))) 
              (expr_term (literal_value (numeric_lit)))))))))