MAYBE

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

Proof:
 Open