We use ideas from [NPS95] and [PW95] to derive a new proof technique for algebraic characterizations of Petri net languages.

[NPS95]

M. Nielsen, L. Priese, V. Sassone, ``Characterizing Behavioural Congruences for Petri Nets''. In Lecture Notes in Computer Science Vol. 962, pp.175-189, 1995.

[PW95]

L. Priese, H. Wimmel, ``On Some Compositional Petri Net Semantics''. Technical Report. In Fachberichte Informatik 20/95, Universität Koblenz-Landau, 1995.