5.1311 When we infer q from p C q and Pp, the relation between the
propositional forms of 'p C q' and 'Pp' is masked, in this case, by our
mode of signifying. But if instead of 'p C q' we write, for example, 'p|q .
| . p|q', and instead of 'Pp', 'p|p' (p|q = neither p nor q), then the
inner connexion becomes obvious. (The possibility of inference from (x) .
fx to fa shows that the symbol (x) . fx itself has generality in it.)
- -- Wittgenstein, Ludwig