Open Petri Nets (Part 2)

I’d like to continue talking about this paper:

• John Baez and Jade Master, Open Petri nets.

Last time I explained, in a sketchy way, the double category of open Petri nets. This time I’d like to describe a ‘semantics’ for open Petri nets.

In his famous thesis Functorial Semantics of Algebraic Theories, Lawvere introduced the idea that semantics, as a map from expressions to their meanings, should be a functor between categories. This has been generalized in many directions, and the same idea...