This is the second part in a series about diagrammatic reasoning, inspired by e-graphs. Last time, we reviewed the concept of initial functor and showed by example how to calculate with diagrams and initial functors. This time, we make that calculus more systematic and we reconceive e-graphs in terms of initial functors. 1 Weak equivalence of diagrams We’ve been deriving equations by chaining together initial functors between diagrams, going in either direction. Let’s give a name to this ...
