+ x
+ x
) = 2 ? (x
+ x
+ x
), (21) *
2 ? (x
+ x
+ x
) = 4 ? (x
+ x
+ x
), (22) *
4 ? (x
+ x
+ x
) = 3 ? (x
+ x
+ x
), (23) *
3 ? (x
+ x
+ x
) = 2 ? (x
+ x
+ x
), (26) *
2 ? (x
+ x
+ x
) = 4 ? (x
+ x
+ x
), (27) *
4 ? (x
+ x
+ x
) = 3 ? (x
+ x
+ x
), (28) *
(x
+ x
+ x
) = (x
+ x
+ x
), (32) *
(x
+ x