Question:
A lady made a neder that in the next 30 days from now she won't eat bread.
Her husband said on day 1, that if by day 30 his wife won't have eaten anything that is ossur, she shall be divorced from today (le'achar 30 yom me'achshov).
On day 10 the husband was mayfer the neder of his wife.
On day 15 his wife ate bread.
Since her neder was abolished, she wasn't eating something which is ossur, so the get was chal.
If the get was chal (from day 1), he husband couldn't be mayfer her neder, and thus she ate something ossur, and she is not divorced.
If she is not divorced, her husband could be mayfer the neder, and so on...
There is an answer (toisfos), but I wanna see some discussion going on.