5.512 “~p” is true if “p” is false. Thus in the true proposition “~p”, “p” is a false proposition. How can the stroke “~” now bring it to agreement with reality [or: the truth]?

What negates in “~p” is however not the “~” but that which is common to all signs of this notation that negate p.

Thus the common rule according to which “~p”, “~~~p”, “~p v ~p”, “~p. ~p”, etc. etc. (ad infinitum) are constructed. And this commonality mirrors negation.

So “~” negates only within a system of notation. It does not stand for some thing.