Question

I don't think I understand this definition: "Events A1,A2,... are mutually exclusive iff A_i U A_j = {} when i and j aren't equal" But wouldn't that mean that if A_i or A_j are non-empty they aren't mutually exclusive?

Answer 1

It should be an intersect symbol and not a union symbol.

Answer 2

If their union was empty, then both sets would be empty.

Answer 3

Thanks, I thought so but that's how it was printed in the litterature thus I became uncertain.

Answer 4

yeah that's a big typo lol