English: Two ways of constructing a family of subsets of r items out of n, such that all subsets intersect each other and there are as many subsets as possible (matching the bound of the
Erdős–Ko–Rado theorem): left, a family formed by fixing one item x and choosing the other r − 1 items in all possible ways; right (for n = 2r), a family formed by avoiding one item x and choosing r of the remaining items in all possible ways. In this example, n = 4 and r = 2; the largest possible intersecting families of subsets have three sets.
The person who associated a work with this deed has dedicated the work to the
public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
http://creativecommons.org/publicdomain/zero/1.0/deed.enCC0Creative Commons Zero, Public Domain Dedicationfalsefalse
Add a one-line explanation of what this file represents