Fuzzy time Petri net primitives for processing fuzzy temporal knowledge

A model for processing fuzzy temporal knowledge, which is based on primitives derived from originally defined Fuzzy Time Petri Nets (FTPN), is proposed in this paper. The primitives are building blocks of the proposed model. The primitives consist of places, transition and fuzzy time token(s). The places represent concepts such as actions, states and events. Transition represents a (fuzzy) time relation between concepts. Fuzzy time tokens carry temporal information and give dynamic properties to the FTPN. Each temporal linguistic expression which describes temporal relation between actions, states or events ("approximately at the same time", "as soon as last/first", "a few moments before/after" etc.) corresponds to one FTPN primitive. The FTPN primitives can be combined and connected into complex forms in order to represent fuzzy temporal knowledge and to support the reasoning and planning in temporally rich domains.