TLDR: If you have a function from b to c and a function from a to b then if you run the second function before the first one you can see the whole thing as a f

TLDR: If you have a function from b to c and a function from a to b then if you run the second function before the first one you can see the whole thing as a function from a to c. It even works with multiple arguments of type b by converting them all before hand, no kidding.