Extended real line

The extended real line $[- \infty, \infty]$ consists of the real numbers with additional elements ${- \infty, \infty}$ such that $- \infty \leq 𝑥 \leq \infty$ for all $𝑥 \in ℝ$ $\infty \geq 𝑥$ . anal Thus it is the Dedekind-MacNeille completion of the reals and the rationals.