Dr. Eugenia Cheng ‘s Lectures on Category Theory (2007)
1. Definition of Monad, Example: Monad for Monoids
The name “monad” came from “monoid” and “triad”, which indicated that it is a triple (1 functor + 2 trasformations), monoidic algebraic structure.
Monad = Monoid + Triad
Monad = Monoid (restricted to endofunctors)
Note: She was annoyed nobody had corrected her mistake in (red) Tμ . (I discovered it only on 2nd revision view few years later).
2. Example2: Monad for Categories
Monad for Small Categories (= Set)
3. Algebra = Monad
What is the difference between Monoid and Monad? (Bartosz Milewski )
Monad (图解) : 单子