  We review some of the endeavors in trying to connect Petri nets with free
symmetric monoidal categories. We give a list of requirement such connections
should respect if they are meant to be useful for practical/implementation
purposes. We show how previous approaches do not satisfy them, and give
compelling evidence that this depends on trying to make the correspondence
functorial in the direction from nets to free symmetric monoidal categories, in
order to produce an adjunction. We show that dropping this immediately honors
our desiderata, and conclude by introducing an Idris library which implements
them.
