From Primal Infon Logic with Individual Variables to Datalog

The logic core of Distributed Knowledge Authorization Logic, DKAL, is constructive logic with a quotation construct “said”. This logic is known as the logic of infons. The primal fragment of infon logic is amenable to linear time decision algorithms when policies and queries are ground. In the presence of policies with variables and implicit universal quantification, but no functions of positive arity, primal infon logic can be reduced to Datalog. We here present a practical reduction of the entailment problem for primal infon logic with individual variables to the entailment problem of Datalog.