title: Meta-logical problems: knights, knaves, and Rips.
authors.affiliation: Department of Psychology, Princeton University, NJ 08544.
authors.forename: P N
authors.initials: PN
authors.lastname: Johnson-Laird
authors.forename: R M
authors.initials: RM
authors.lastname: Byrne
mesh_terms: D003210:Concept Formation; D006801:Humans; D008128:Logic; D011340:Problem Solving; D011578:Psycholinguistics; D012660:Semantics