Pathway II

∞Extended number systems

Add infinities to the line. Extended reals and the compactification that makes ±∞ points.

1. 01Extended realsThe extended real line is ℝ with two extra points, +∞ and −∞, sitting at the ends.4 min
2. 02One-point compactificationGlue the two infinities into one. The real line becomes a circle — ℝP¹.4 min