Cave ab homine unius libri
Cave ab homine unius libre
with disagreement as to the declension of liber (book). Now, I looked it up, and it looks to me like BOTH are wrong. "With Book" should be the ablative, yes? In which case it should be:
Cave ab homine unius libro
Libri is genitive singular, and libre is not a form of liber at all.
And now to confuse the issue even further, homine is the singular ablative of homo. Shouldn't it be accusative (object of cave), which would be hominem? That would be consistent with Cave canem.
So now I'm down to:
Cave ab hominem unius libro
Can anyone confirm or correct me on this???
EDIT: I suppose the genitive for libri could be correct if you mean to imply the man is of the book; i.e owned or governed by the book. But still you would need hominem, yes?
EDIT AGAIN: OK the preposition "ab" seems to be misplaced, and confusing the structure here. Dropping it, one gets a simple sentence..
CAVE HOMINEM UNIUS LIBRI beware a man of [governed by] one book