Sets (cardinality)

Mar 2017
1
0
canada
What is meant by odd and even cardinality in set theory. What are formulas to use them?
 
Last edited by a moderator:

skipjack

Forum Staff
Dec 2006
21,481
2,470
Do you still need help with this?
 

mathman

Forum Staff
May 2007
6,932
774
I presume the terms refer only to sets with finite number of elements.
 

Country Boy

Math Team
Jan 2015
3,261
899
Alabama
For finite sets, the "cardinality" is just the number of elements in the set. A set has even cardinality if it contains an even number of elements and has odd cardinality if it contains an odd number of elements. {a, b, c} has three elements so has odd cardinality. {a, b, c, d} has four elements so has even cardinality.