< mathematics > 1. Bigger than any natural number . There are various formal set definitions in set theory : a set X is infinite if
(i) There is a bijection between X and a proper subset of X.
(ii) There is an injection from the set N of natural numbers to X.
(iii) There is an injection from each natural number n to X.
These definitions are not necessarily equivalent unless we accept the Axiom of Choice .
2. The length of a line extended indefinitely.
See also infinite loop , infinite set .
[ Jargon File ]
(1995-03-29)