This is a set of Functional Combinators of Lambda Calculus for functional programming, as well as some concepts such as recursion, partial application, combinators, currying, THE TRUTH defined in lambda, etc.
Some of this functions are fom a Lambda talk that I saw online, if you really want a nice and complete documentation of combinators and lambda calculus in general, I definetly recommend checking out lambda-talk repo and the YouTube Videos from Gabriel Lebec
This is also a great talk. Jeremy Fairbank shows a set of concepts and functional programming structures for JavaScript today. Again, if you want to know more about programming and testing and all that good stuff, checkout Jeremy's YouTube Channel