In the context of a very well fortified place,
what does 入る者なく出る者なし mean?
It seems like it would mean: none may enter, none may leave, but I'd like to make sure, and understand the naku form better.
So I'm pretty sure naku is the adverb form of nai, which is nonexistence. Nashi means "without".
I've also considered naku might be a shortened nakute in the sense of naide/zuni.
Taking these meanings, the sentence would mean: no person enters without leaving, but that doesn't make sense in context. Just based on context, something like none who enter may leave would make sense.
The more I think about it, the more I get confused. Any help?