<Ul> <Li> The set R is a field, meaning that addition and multiplication are defined and have the usual properties . </Li> <Li> The field R is ordered, meaning that there is a total order ≥ such that, for all real numbers x, y and z: <Ul> <Li> if x ≥ y then x + z ≥ y + z; </Li> <Li> if x ≥ 0 and y ≥ 0 then xy ≥ 0 . </Li> </Ul> </Li> <Li> The order is Dedekind - complete; that is: every non-empty subset S of R with an upper bound in R has a least upper bound (also called supremum) in R . </Li> </Ul> <Li> The set R is a field, meaning that addition and multiplication are defined and have the usual properties . </Li> <Li> The field R is ordered, meaning that there is a total order ≥ such that, for all real numbers x, y and z: <Ul> <Li> if x ≥ y then x + z ≥ y + z; </Li> <Li> if x ≥ 0 and y ≥ 0 then xy ≥ 0 . </Li> </Ul> </Li> <Ul> <Li> if x ≥ y then x + z ≥ y + z; </Li> <Li> if x ≥ 0 and y ≥ 0 then xy ≥ 0 . </Li> </Ul>

What is the real number system in math