This repository provides the top-level definition for interpretations of Situations in Logtalk.

Examples include: - SitCalc - STRIPState

A library implementing these protocols is suitable for use with BedSit for developing applications quickly and flexibly.

An additional category is provided to use queries with holds/2.

sitcalc::holds(Query, Situation).

Query what holds in a Situation. Queries can be Fluents, or compound terms with and conjunction, or disjunction, not for Prolog style negation, implies for implication and equivalentTo for equivalence.

Caveats

• For the case not P, Prolog style negation is used (+)
• For the case where P implies Q, P is false, and Q is not ground, we can't unify Q with a false case due to Prolog style negation.
• For the case where P equivalentTo Q if either P or Q are non-ground, only the case where both P and Q are true will hold. So if P is ground to a false case and Q is not ground, then P equivalentTo Q won't hold even if some value of Q would make it so. The same applies if Q is ground to the false case and P is not ground. This is due to the Prolog style negation.