Ah right, I forget that extending with a single infinity element is useful with complex numbers and with geometry. It's still not very common with the reals alo

Ah right, I forget that extending with a single infinity element is useful with complex numbers and with geometry. It's still not very common with the reals alone as +∞ and -∞ are reasonable to want as separate elements there, but it doesn't play nicely with 1/0 that way.