Modality (Logic) Semantics (Philosophy) 3 Description (Philosophy) 2 Necessity (Philosophy) 2 Bisimulation 1 COMPUTERS / Networking / General 1 Coinduction (Mathematics) 1 Computer science 1 Essentialism (Philosophy) 1 Good and evil 1 Grammar, Comparative and general 1 History 1 Induction (Mathematics) 1 Knowledge, Theory of 1 Language and languages 1 Logic 1 Logic, Modern 1 Logic, Symbolic and mathematical 1 Meaning (Philosophy) 1 Modality (Theory of knowledge) 1 Names 1 Predicate calculus 1 Reference (Philosophy) 1 Tense (Logic) 1 Truth 1 Variables (Mathematics) 1