Abstract:
We introduce the notion of strong concatenable process
for Petri nets as the least refinement of non-sequential (concatenable)
processes which can be expressed abstractly by means of a functor
from the category of Petri nets to an appropriate category of
symmetric strict monoidal categories with free non-commutative monoids of
objects, in the precise sense that, for each net N, the strong concatenable
processes of N are isomorphic to the arrows of 
. This yields
an axiomatization of the causal behaviour of Petri nets in terms of symmetric
strict monoidal categories.
In addition, we identify a
coreflection right adjoint to and we characterize its
replete image in the category of symmetric monoidal categories, thus yielding
an abstract description of the category of net computations
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