Issue No. 03 - June (1994 vol. 6)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/69.334863
<p>The formalism of nonmonotonic reasoning has been integrated into logic programming to define semantics for logic program with negation. Because a Petri net provides a uniform model for both the logic of knowledge and the control of inference, the class of high-level Petri nets called predicate/transition nets (PrT-nets) has been employed to study production rule based expert systems and Horn clause logic programs. We show that a PrT-net can implement the nonmonotonicity associated with a logic program with negation as well as the monotonicity of Horn clause logic program. In particular, we define a semantics for a normal logic program and implement it with PrT-net. We demonstrate that in the presence of inconsistency in a normal logic program, the semantics still works well by deducing meaningful answers. The variations and potential applications of the PrT-net are also addressed.</p>
nonmonotonic reasoning; logic programming; Petri nets; expert systems; Horn clauses; high-level Petri net model; normal logic program; negation; nonmonotonic reasoning; logic programming; semantics; uniform model; inference control; predicate/transition nets; PrT-nets; production rule based expert systems; Horn clause logic programs; inconsistency
L. Li, "High-Level Petri Net Model of Logic Program with Negation," in IEEE Transactions on Knowledge & Data Engineering, vol. 6, no. , pp. 382-395, 1994.