Partially uniform k-quandles

OK, so perhaps not a joke, but I was rather amused when I read a recent article by Mark Jason Dominus on cases in which some statement S was considered to be proved, and later turned out to be false.

As an example of "rather obscure technical matters" which he didn't want to include in the article, he gave the case where Professor Snorfus publishes in Acta Quandalia that all partially uniform k-quandles have the Cosell property, and this goes unchallenged for several years before one of the other three experts in partially uniform quandle theory notices that actually this is only true for Nemontovian k-quandles.

I laughed :)

Nur fliegen ist schöner

I just found a flight which would cost the three of us 219 euros to Zurich and back—if we flew there and back on Tuesday instead of Monday.

That's hard to beat with the train.