The work of Carl Adam Petri is presented in a correct and comprehensive way. There are only the following remarks.
Section: Anatomy of a Petri net
The phrase "Offices like D and F are rare in human organizations but they do exist, e.g. in the military." should be explained or omitted, in particular the e.g. is completely unclear.
Section: Marking class, safety, security, and fairness:
In the text beside Figure 9: "... graphs from basic nets (Fig. )." (number of Figure is missing)