well-ordering

Least-element property ordering

Well-ordering is a mathematical property of a set: every nonempty subset has a least element.

The natural numbers are well-ordered under their usual ordering—any collection of them contains a smallest.

The real numbers are not well-ordered, since an interval like (0,1) has no minimum.

The well-ordering principle states that any set can be well-ordered, a claim equivalent to the axiom of choice.

set-theory

axiom

Self-evident starting principle

successor · totality · comparability · subset · chain · enumeration · trichotomy · foundation · countable

structure

hierarchy

Ranked authority structure

chain · embedding · isomorphism · monotone · bounded

proof

induction

Formal admission process

Categories
Opposites
order completeness

well-orderingpreorder

Buy before availability

incomparability

GENERAL ORDER vs. STRUCTURED ORDER

well-orderingchaos

Complete disorder and confusion

disorder

Family

well, order, ordinary, ordered, orders, ordering, coordinate, disordered, reorder

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