An interesting approach is join calculus. This tutorial builds on the same "chemical" metaphor used in the article https://sites.google.com/site/winitzki/tutor

An interesting approach is join calculus. This tutorial builds on the same "chemical" metaphor used in the article https://sites.google.com/site/winitzki/tutorial-on-join-calculus-and-its-implementation-in-ocaml-jocaml https://sites.google.com/site/winitzki/tutorial-on-join-calc...