MAYBE

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

Proof:
 Open