universe

n 1: everything that exists anywhere; "they study the evolution

of the universe"; "the biggest tree in existence" [syn:

{existence}, {nature}, {creation}, {world}, {cosmos}, {macrocosm}]

2: the whole collection of existing things [syn: {cosmos}]

3: (statistics) the entire aggregation of items from which

samples can be drawn; "it is an estimate of the mean of

the population" [syn: {population}]

4: everything stated or assumed in a given discussion [syn: {universe

of discourse}]

inverse

Given a {function}, f : D -> C, a function g : C

-> D is called a left inverse for f if for all d in D, g (f d)

◦ d and a right inverse if, for all c in C, f (g c) ◦ c and an

inverse if both conditions hold. Only an {injection} has a

left inverse, only a {surjection} has a right inverse and only

a {bijection} has inverses. The inverse of f is often written

as f with a -1 superscript.

(1996-03-12)