Axioms

In order to define the real numbers, we need a set of axioms that the real numbers will obey.

Axiomatic definition

Axioms

The real numbers are a set denoted by \mathbb{R}, such that the following properties hold

(R1) \mathbb{R} is a field under addition and multiplication.

(R2) \mathbb{R} is totally ordered for some \leq.

(R3) Addition and multiplication preserve order.

(R4) Every non-empty subset of \mathbb{R} that is bounded above has a least upper bound.