Applicativelaws and property tests
Traversable: what and why and what does this have to do with
Monad and monad transformers
Monad: what and why
The Kleisli fish
Monad laws and property tests
Monads do not compose: monad transformers
Interlude: An X that is not a Y
Contravariant: what and why
Contravariantlaws and property tests
Profunctor: what and why
Profunctorlaws and property tests
Arrow: What is this madness?
Wrapping up: So, then, what is functoriality?