What Does A (+) B Represent in Set Theory?

[Goldenwind]

[SOLVED] Quick, simple question on sets

Homework Statement

A - B is the difference
A u B is the union
A n B is the intersection
A (+) B is what?

I would google this, but I haven't a clue what the symbol or function is called. It's supposed to be a +, inside a circle.

Can someone tell me what this symbol means, or at least tell me what it's called, so I can look it up myself?

Edit: In TeX, it's this: \oplus

 

[Goldenwind]

Found it.

For anyone else with a similar problem, it's the "symmetric difference"

A (+) B = AuB - AnB
(The set of elements in either A or B, but not in both)