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LANGER, SUSANNE K (1953)(1967) An Introduction to Symbolic Logic, Dover Publications, New York.
Universe class
'Suppose in a given universe of discourse, we form a class A such that "x ε A" holds for all values of x, i.e. such that (x) : x ε A." (123).
This means x is equal to A.
ε is epsilon from the Greek alphabet meaning is, a. The ε symbol, according to Langer is specifically meant as a symbol for is, a, in contrast with any symbol for is.
Langer, noting earlier in her text, mentions 'nt' which is documented as houses north of. (123).
nt = north of
˜ = not
(x) : ˜ (x nt x) (123).
x is not north of x.
(v): ˜ (v nt v)
Vancouver is not north of Vancouver. Something is not north of itself.
Langer states this is a universe class. (123). Any statement about everything concerns a universe class. (123). Every statement about nothing is also a universe class. (124). Langer writes that what is 'true for nothing is false for anything.' (124).
My example:
It is not true that the finite is infinite.
It is false that anything finite is infinite.
