Recently I have been wondering what different notions of equivalence are possible. Thinking about one of my favorite fourfolds — Structure-Function — with help from the fourfold of The One and the Many, I have (naturally) come up with four notions: Identities, Isomorphisms, Confluences, and Indiscernibles. Identities: One as One. In mathematics, an identity is … Continue reading Notions of Equivalence