Tag Archives: projective plane

Pseudofields, quasifields, near-domains

Here is a piece of evidence which those who think that mathematics is invented rather than discovered will like. This concerns definitions. I wrote last year about the definitions of a group, a matroid, the real numbers, and primitivity. In … Continue reading

Posted in doing mathematics, exposition, history | Tagged , , , , , | 2 Comments

Kirkman’s schoolgirls and their friends

Often it happens that, when I think about a hard problem, I am absolutely convinced that I know what the answer will be, but I merely lack a proof. In this post I want to discuss a problem which I … Continue reading

Posted in exposition, open problems | Tagged , , , , , | 5 Comments