History
The stroke is named after Henry M. Sheffer, who provided (Sheffer 1913) an axiomatization of Boolean algebras using the stroke, and proved its equivalence to a standard formulation thereof by Huntington employing the familiar operators of propositional logic (and, or, not). Because of self-duality of Boolean algebras, Sheffer's axioms are equally valid for either of the NAND or NOR operations in place of the stroke. Sheffer interpreted the stroke as a sign for non-disjunction (NOR) in his paper, mentioning non-conjunction only in a footnote and without a special sign for it. It was Jean Nicod who first used the stroke as a sign for non-conjunction (NAND) in a paper of 1917 and which has since become current practice.
Charles Sanders Peirce (1880) had discovered the functional completeness of NAND or NOR more than 30 years earlier, using the term ampheck (for ‘cutting both ways’), but he never published his finding.
Read more about this topic: Sheffer Stroke
Famous quotes containing the word history:
“Psychology keeps trying to vindicate human nature. History keeps undermining the effort.”
—Mason Cooley (b. 1927)
“What would we not give for some great poem to read now, which would be in harmony with the scenery,—for if men read aright, methinks they would never read anything but poems. No history nor philosophy can supply their place.”
—Henry David Thoreau (1817–1862)
“The one duty we owe to history is to rewrite it.”
—Oscar Wilde (1854–1900)