Last chapter Logical agents apply inference to a knowledge base to derive new information and make decisions Basic concepts of logic: ~syntax(语法)：formal structure of sentences =semantics (语义：truth of sentences wrt.models entailment (蕴涵)：necessary truth of one sentence given another inference (推理)：deriving sentences from other sentences soundness (可靠性)：derivations produce only entailed sentences completeness (完备性)：derivations can produce all entailed sentences Forward,backward chaining are linear-time,complete for Horn clauses Resolution is complete for propositional logic Propositional logic lacks expressive power 口◆461三1，是90C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Last chapter ▶ Logical agents apply inference to a knowledge base to derive new information and make decisions ▶ Basic concepts of logic: ▶ syntaxffffffff(语法): formal structure of sentences ▶ semanticsffffffff(语义): truth of sentences wrt. models ▶ entailmentffffffff(蕴涵): necessary truth of one sentence given another ▶ inferenceffffffff(推理): deriving sentences from other sentences ▶ soundnessffffffffff(可靠性): derivations produce only entailed sentences ▶ completenessffffffffff(完备性): derivations can produce all entailed sentences ▶ Forward, backward chaining are linear-time, complete for Horn clauses ▶ Resolution is complete for propositional logic ▶ Propositional logic lacks expressive power