Three standard Peter Lax jokes (heard in his lectures) :
1. What's the contour integral around Western Europe?
Answer: Zero, because all the Poles are in Eastern Europe!
Addendum: Actually, there ARE some Poles in Western Europe, but
they are removable!
2. An English mathematician (I forgot who) was asked by his very religious
colleague:
Do you believe in one God?
Answer: Yes, up to isomorphism!
3. What is a compact city?
It's a city that can be guarded by finitely many near-sighted
policemen!
W H Y C O P S H A T E Y O U <<<<&l <
-if you have to ask get out of the way-
Have you ever been stopped by a traffic cop and, while he was
writing a ticket or giving you a warning, you got the feeling that
he would just love to yank you out of the car, right through the
window, and smash your face into the front fender?...