There's also the projectively extended definition, where positive and negative infinity are defined to be the same thing. It has some nice properties like divis

There's also the projectively extended definition, where positive and negative infinity are defined to be the same thing. It has some nice properties like division by zero is defined, but you lose total ordering of course. In a way that's a good thing though because you don't have to worry about how "big" an infinity is: it's just a symbol. https://en.wikipedia.org/wiki/Projectively_extended_real_line https://en.wikipedia.org/wiki/Projectively_extended_real_lin...