Mathematician, outstanding teacher, and UseNet kook.
Wrote three books, including Boolean Rings and The Theory of Sets and Transfinite Arithmetic. It is a very, very easy book. It's still real math. A lot of the reason it's easy is Abian's superb English description of the contents. You can actually read the English without the symbology and get about 80% of the book. And then the meaning of the symbols is just obvious. If it can be done once, why can't it be done all the time?
Yes I know it is the same Abian. I picked him because, damnit, the guy's book is really superb. His still rarer work, BooleanRings, is even better. Just what drove Abian to become net.kooky is a good question. A calm warm intellect shines like a beacon from his books. I wonder if there is any bio available that would explain what happened to him.
Not senile dementia. He was publishing good math papers up until his death in 1999.