In set theory, what does |A| mean if A is a set?

[Leros]

I have a book with three chapters on sets, but it never uses this syntax. If you have a set A, what is |A|?

 

[Pepsi1337]

http://mathworld.wolfram.com/

and

http://www.wikipedia.org/

are better teachers than your professors.

 

[her209]

cardinality

 

[Leros]

Its hard to search for a symbol.

 

[SsupernovaE]

Originally posted by: Pepsi1337
http://mathworld.wolfram.com/

and

http://www.wikipedia.org/

are better teachers than your professors.

Sadly, you may be correct : (

 

[SsupernovaE]

Originally posted by: Leros
Its hard to search for a symbol.

Too lazy to look for, but I think there's a Wikipedia article listing all of the logic symbols for logic and math

Here you go, http://en.wikipedia.org/wiki/T...f_mathematical_symbols

 

[her209]

Originally posted by: Leros
Its hard to search for a symbol.

Its cardinality!!!!

 

[Leros]

Originally posted by: her209
cardinality

Thank you, just flipped to the cardinality section of my book and that syntax wasn't used. Stupid professors not having books for their class then expecting us to look stuff up but not realizing that different people use different syntax. Argh.