AIMA.Core.Logic.FOL.Inference.FOLBCAsk.folbcask C# (CSharp) Метод

        private List<List<ProofStepBwChGoal>> folbcask(FOLKnowledgeBase KB,
                BCAskAnswerHandler ansHandler, List<Literal> goals,
                Dictionary<Variable, Term> theta)
        {
            List<List<ProofStepBwChGoal>> thisLevelProofSteps = new List<List<ProofStepBwChGoal>>();
            // local variables: answers, a set of substitutions, initially empty

            // if goals is empty then return {theta}
            if (goals.Count==0)
            {
                thisLevelProofSteps.Add(new List<ProofStepBwChGoal>());
                return thisLevelProofSteps;
            }

            // qDelta <- SUBST(theta, FIRST(goals))
            Literal qDelta = KB.subst(theta, goals[0]);

            // for each sentence r in KB where
            // STANDARDIZE-APART(r) = (p1 ^ ... ^ pn => q)
            foreach (Clause r in KB.getAllDefiniteClauses())
            {
                Clause r2 = KB.standardizeApart(r);
                // and thetaDelta <- UNIFY(q, qDelta) succeeds
                Dictionary<Variable, Term> thetaDelta = KB.unify(r2.getPositiveLiterals()
                        [0].getAtomicSentence(), qDelta.getAtomicSentence());
                if (null != thetaDelta)
                {
                    // new_goals <- [p1,...,pn|REST(goals)]
                    List<Literal> newGoals = new List<Literal>(r2
                            .getNegativeLiterals());
                    newGoals.AddRange(goals.Skip(1));
                    // answers <- FOL-BC-ASK(KB, new_goals, COMPOSE(thetaDelta,
                    // theta)) U answers
                    Dictionary<Variable, Term> composed = compose(KB, thetaDelta, theta);
                    List<List<ProofStepBwChGoal>> lowerLevelProofSteps = folbcask(
                            KB, ansHandler, newGoals, composed);

                    ansHandler.addProofStep(lowerLevelProofSteps, r2, qDelta,
                            composed);

                    thisLevelProofSteps.AddRange(lowerLevelProofSteps);
                }
            }

            // return answers
            return thisLevelProofSteps;
        }