assign(max_seconds, 30).

formulas(sos).

(x * e) * x = x.
x * (x * y) = y.
(x * y) * (z * u) = (x * z) * (y * u).
((x * x) * x) * x = e.

end_of_list.

formulas(goals).

x * y = x * z -> y = z.

end_of_list.
