The term used in propositional calculus for the NAND connective.
The notation 
is used for this connective, a most unfortunate choice in light of modern usage of
or 
to denote OR.
Alternative Denial
See also
Joint Denial, NANDExplore with Wolfram|Alpha
References
Mendelson, E. Introduction to Mathematical Logic, 4th ed. London: Chapman & Hall, p. 26, 1997.Referenced on Wolfram|Alpha
Alternative DenialCite this as:
Weisstein, Eric W. "Alternative Denial." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/AlternativeDenial.html