Math is turning bad

Psst, c'mere, said the shifty-eyed man wearing a long black trenchcoat, as he beckoned me off the rainy street into a damp dark alley. I followed.

What are you selling? I asked.

Geometrical algebra drugs.

Huh!?

Geometry drugs. Ya got your uppers, your downers, your sidewaysers, your inside-outers...

Stop right there, I interrupted. I've never heard of inside-outers.

Oh, man, you'll love 'em. Makes you feel like M.C. ever-lovin' Escher on a particularly weird day.

Go on...

OK, your inside-outers, your arbitrary bilinear mappers, and here, heh, here are the best ones, he said, pulling out a large clear bottle of orange pills.

What are those, then? I asked.

Givens transformers. They'll rotate you about more planes than you even knew existed.

Sounds gross. What about those bilinear mappers?

There's a whole variety of them. Here's one you'll love -- they call it 'One Over Z' on the street. Take one of these little bad boys and you'll be on speaking terms with the Point at Infinity.