Category Theory Demonstrations

I've been experimenting with category-theory algorithms written in Jan Wielemaker's SWI-Prolog. Some are adapted from David Rydeheard and Rod Burstall's book Computational Category Theory. I'm hoping to produce an assortment of demos, including animations, to illustrate various points of category theory. As a beginning, here are a few simple demos, text only, relating to initial and terminal objects, products, and coproducts in the category of finite sets. At the moment, they're as much to test my functions for generating and displaying examples as anything else.

In the text that the demos display, I've used the same notation as in some examples by Avery Andrews in Wikiversity's Introduction to Category Theory/Products and Coproducts.

Either or

or

let A= a set chosen at random {a} {b} {c} {a,b} {a,b,c} {a,b,c,d} {a,b,c,d,e} and B= a set chosen at random {a} {b} {c} {x} {a,b} {x,y} {a,b,c} {x,y,z} {a,b,c,d} {x,y,z,t} {a,b,c,d,e} {x,y,z,t,u} then either: or or . or .