On the other hand, problems 1, 2, 5, 9, 15, 18, and 22 have solutions that have partial acceptance, but there exists some controversy as to whether they resolve the problems.
Por outra banda, os problemas 1, 2, 5, 9, 15, 18*, 21 e 22 teñen solucións de aceptación parcial, pero existe certa controversia ao respecto de se a solución resolve realmente o problema.