Integer - Order-theoretic Properties

Order-theoretic Properties

Z is a totally ordered set without upper or lower bound. The ordering of Z is given by:

... −3 < −2 < −1 < 0 < 1 < 2 < 3 < ...

An integer is positive if it is greater than zero and negative if it is less than zero. Zero is defined as neither negative nor positive.

The ordering of integers is compatible with the algebraic operations in the following way:

1. if a < b and c < d, then a + c < b + d
2. if a < b and 0 < c, then ac < bc.

It follows that Z together with the above ordering is an ordered ring.

The integers are the only integral domain whose positive elements are well-ordered, and in which order is preserved by addition.