A characteristic of a composite symbol: it has something: in common with other symbols.

5.5262 The truth or falsehood of *every* proposition alters
something in the general structure of the world.
And the range which is allowed to its structure by
the totality of elementary propositions is exactly
that which the completely general propositions
delimit.

(If an elementary proposition is true, then, at
any rate, there is one *more* elementary proposition
true.)

5.53 Identity of the object I express by identity of the sign and not by means of a sign of identity. Difference of the objects by difference of the signs.

5.5301 That identity is not a relation between objects is
obvious. This becomes very clear if, for example,
one considers the proposition ""
What this proposition says is simply that *only*
satisfies the function , and not that only such
things satisfy the function which have a certain
relation to .

One could of course say that in fact *only*
has this relation to but in order to express
this we should need the sign of identity itself.

.5302 Russell's definition of "" won't do; because
according to it one cannot say that two objects
have all their properties in common. (Even if
this proposition is never true, it is nevertheless
*significant*.)

5.5303 Roughly speaking: to say of *two* things that
they are identical is nonsense, and to say of *one*
thing that it is identical with itself is to say
nothing.

5.531 I write therefore not "" but "" (or ""). And not "" but ""

5.532 And analogously : not "",