Set-Theoretic View of Function Composition

Explanations 2

• Of course we already know of functions f:A→Bf : A \to Bf:A→B. Another way of writing this is A→fB.A \stackrel{f}{\to} B.A→fB. This emphasizes that fff is in fact a map taking el…

  By Evan Chen, Brian Chen, Victor Wang

• You're probably sick of sets of real numbers and functions on real numbers. So if you want, let's take a break from that. (But otherwise, see Evan's alternative explanation.) Le…

  By Victor Wang, Michael Godfrey, Victor Wang