The definition given was 'if there is another ordinal π½ such that 2β π½=πΌ' [1], but the intuition is better explained by the post below:
> A set π has even cardinality if it can be written as the disjoint union of two subsets π΄,π΅ which have the same cardinality. [2]
In other words, a set is even if it can be paired up, by finding one grouping where it pairs. Finding alternative groupings that do not pair does not matter.
> A set π has even cardinality if it can be written as the disjoint union of two subsets π΄,π΅ which have the same cardinality. [2]
In other words, a set is even if it can be paired up, by finding one grouping where it pairs. Finding alternative groupings that do not pair does not matter.
[1] https://math.stackexchange.com/a/49046
[2] https://math.stackexchange.com/a/49045