Example image of eyePlorer eyePlorer map for 'Entailment': Binary relation Logic Mathematics Model theory Proposition Valuation Antecedent Consequent Corresponding conditional (logic) Element (mathematics) Logical conjunction Material conditional Empty domain Type signature Validity Compactness theorem Deduction Equivalence Leon Henkin Second-order logic Deduction theorem Alan Turing Alonzo Church Effective method Emil Leon Post Jacques Herbrand Kurt Gödel Relevance logic Boolean function Truth table Logical connective Truth value Set theory Universal quantification Conjunction Logical biconditional Logical disjunction Negation Existential quantification Identity function Algebra of sets Subset Counterfactual conditional Equivocation Indicative conditional Tautology (logic) J. Barkley Rosser Stephen Cole Kleene Implication graph Monotonicity of entailment