Example image of eyePlorer eyePlorer map for 'Sheffer stroke': Boolean function Henry M. Sheffer Logical conjunction Logical connective Negation Propositional calculus Vertical bar Boolean algebra (logic) Digital electronics Charles Sanders Peirce Duality (mathematics) Formal system Functional completeness Logical NOR Willard Van Orman Quine Central processing unit Flash memory Proposition Truth value Truth table Venn diagram Logical disjunction Material conditional Linear Monotonic function Well-formed formula Existential graph Polish notation Jean Nicod Table of logic symbols Universal quantification Intuitionistic logic Nand Josiah Royce Tractatus Logico-Philosophicus Boolean algebras canonically defined First-order logic Type theory Laws of Form DEC Alpha Symmetry Propositional formula