RELAX NG implementation of P/T nets defined as a restricted form of High-Level Petri Net Graphs. This type allows the use of the built-in sorts Dots and Bool only. File name: pt-hlpng.pntd Version: 2009 (c) 2007-2009 Lom Hillah (AFNOR) Revision: July 2008 - L.H The HL Core Structure grammar must be used to replace the definition of the Type of a place. The other constraints are captured in the UML diagram which models this new Petri net type. Basically, all transition condition must be set to the constant 'true' and arc annotations and initial markings are ground terms of the multiset sort over Dot (See Dot and Terms grammar). The URI value for the net type attribute, declaring the type (and subsequently the namespace) of P/T nets as a restricted form of HLPNGs. http://www.pnml.org/version-2009/grammar/pt-hlpng Re-defining the 'Type' label for a place. It must refer to the built-in sort Dot if mentioned. Since it is optional, it must be assumed that the type is Dot if not mentioned. This is possible because of the declared named space.