< mathematics > A set with a total ordering and no infinite descending chains . A total ordering " x x x x x = y
for all x, y: x In addition, if a set W is well-ordered then all non-empty subsets A of W have a least element, i.e. there exists x in A such that for all y in A, x Ordinals are isomorphism classes of well-ordered sets , just as integers are isomorphism classes of finite sets.
(1995-04-19)