ekmett
profunctor
category theory
endofunctor
free monad
semigroup
commutative diagram
lambda calculus
combinator
rank-n types
impredicative types
undecidable superclasses
monoid
prism
lens
monomorphic
distributed
idris
dependent types
cartesian closed
value polymorphism
contravariant
associativity
kleisli category
simplify the types