MAYBE

Problem:
 0(1(1(2(2(x1))))) -> 0(0(3(1(x1))))
 3(2(4(4(1(3(x1)))))) -> 3(5(1(3(1(x1)))))
 4(3(2(0(4(1(x1)))))) -> 5(4(2(5(1(x1)))))
 2(4(4(4(5(0(4(x1))))))) -> 2(3(2(5(2(3(2(0(x1))))))))
 5(3(5(0(2(3(2(x1))))))) -> 5(4(2(3(4(1(2(x1)))))))
 5(4(0(2(5(3(4(0(x1)))))))) -> 3(5(0(1(5(4(0(x1)))))))
 5(3(0(0(0(4(1(5(5(x1))))))))) -> 5(4(5(5(1(5(2(5(x1))))))))
 1(1(3(3(3(1(5(0(2(4(x1)))))))))) -> 1(1(2(5(5(3(2(5(0(x1)))))))))
 0(2(0(0(3(3(5(4(1(4(0(x1))))))))))) -> 0(2(3(4(1(0(3(5(3(5(x1))))))))))
 1(1(0(1(3(3(0(1(3(2(5(x1))))))))))) -> 1(0(0(4(4(4(4(1(4(5(x1))))))))))
 3(3(3(3(1(0(1(4(3(1(2(x1))))))))))) -> 3(5(2(0(4(5(1(0(2(0(2(x1)))))))))))
 3(4(2(3(2(1(5(4(2(4(2(x1))))))))))) -> 5(0(2(5(0(4(1(3(4(x1)))))))))
 2(0(0(3(1(2(1(0(4(2(4(0(x1)))))))))))) -> 2(1(1(0(3(0(2(0(4(1(1(x1)))))))))))
 4(1(5(1(4(5(0(3(1(5(2(4(x1)))))))))))) -> 5(0(0(2(2(2(5(3(2(4(1(4(4(x1)))))))))))))
 4(4(5(5(5(1(3(2(5(4(4(3(x1)))))))))))) -> 5(4(2(5(4(4(5(2(3(1(2(3(x1))))))))))))
 3(2(4(2(5(1(3(4(5(1(4(5(2(x1))))))))))))) -> 5(1(0(4(0(1(1(3(2(0(1(5(2(x1)))))))))))))
 4(5(3(1(5(4(4(5(2(5(2(5(0(4(x1)))))))))))))) -> 5(4(4(4(2(5(4(1(4(4(5(4(0(0(4(x1)))))))))))))))
 0(4(4(4(0(5(2(1(5(0(3(1(0(1(4(x1))))))))))))))) -> 0(3(5(5(2(0(3(5(3(3(1(2(5(4(x1))))))))))))))
 4(2(0(2(5(3(1(0(2(1(0(0(4(3(0(x1))))))))))))))) -> 0(2(0(0(3(2(1(5(2(4(1(2(1(4(1(x1)))))))))))))))
 5(1(4(5(3(3(0(5(2(1(0(2(5(1(4(x1))))))))))))))) ->
 5(4(1(3(3(4(2(1(1(4(1(2(0(3(2(4(x1))))))))))))))))
 4(0(5(3(4(4(5(2(2(2(1(0(0(3(4(4(x1)))))))))))))))) ->
 5(2(2(5(0(3(2(2(3(0(2(0(3(2(3(2(4(x1)))))))))))))))))
 3(0(0(5(3(2(3(5(3(5(0(3(3(2(1(3(3(x1))))))))))))))))) ->
 1(1(5(3(4(2(4(2(5(1(4(2(2(5(1(5(3(1(x1))))))))))))))))))
 0(0(4(3(4(5(2(1(1(1(5(1(2(5(3(3(1(5(x1)))))))))))))))))) ->
 0(0(0(4(3(0(4(0(2(5(4(3(1(4(3(3(1(5(x1))))))))))))))))))
 4(5(5(3(4(4(2(2(0(3(1(1(1(0(4(2(0(4(x1)))))))))))))))))) ->
 5(2(3(0(2(4(2(3(2(3(2(5(2(5(1(0(3(4(x1))))))))))))))))))
 0(0(0(4(4(2(3(4(5(0(3(1(2(5(5(1(3(4(4(x1))))))))))))))))))) ->
 0(0(2(2(1(0(5(5(1(2(5(2(3(4(5(5(5(1(0(x1)))))))))))))))))))
 4(2(0(1(5(1(4(4(4(3(2(5(1(5(1(3(2(0(0(x1))))))))))))))))))) ->
 5(2(5(4(5(5(5(3(5(3(2(3(4(0(5(x1)))))))))))))))
 5(2(2(5(0(0(0(3(1(3(3(3(4(3(1(4(2(4(1(x1))))))))))))))))))) ->
 5(2(3(4(4(4(3(4(5(5(0(5(5(5(2(5(x1))))))))))))))))
 0(2(4(1(1(2(4(2(0(1(4(4(5(5(0(4(0(3(1(5(5(x1))))))))))))))))))))) ->
 5(5(0(4(1(2(3(5(1(2(1(4(1(0(5(3(5(3(5(x1)))))))))))))))))))
 1(3(2(2(2(0(4(5(2(5(3(5(5(3(4(4(2(3(0(0(0(x1))))))))))))))))))))) ->
 1(3(3(3(2(5(4(2(4(0(5(4(4(5(4(3(2(0(0(4(x1))))))))))))))))))))
 5(2(1(4(1(2(3(4(1(3(5(0(4(3(3(5(5(3(5(2(5(x1))))))))))))))))))))) ->
 5(2(1(2(5(5(0(5(1(2(1(5(5(4(3(2(2(5(0(3(5(x1)))))))))))))))))))))

Proof:
 Open