The functions f and g defined on the power set 2^S of a finite set S are if it satisfies the following conditions, This form is the Möbius inversion formula in adjacent algebra of the semi-ordered set 2^S.

src: Inclusion-elimination principle - Wikipedia


This page is auto-translated from /nishio/包除原理とメビウスの反転公式 using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I’m very happy to spread my thought to non-Japanese readers.