Definition:Logical NAND/Notational Variants

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Various symbols are encountered that denote the concept of logical NAND:

Symbol Origin Known as
$p \mid q$ Henry Sheffer Sheffer stroke
$p \uparrow q$ Also sometimes referred to as the Sheffer stroke
$p \mathop {\mathsf {NAND} } q$
$p \mathop / q$ 1959: A.H. Basson and D.J. O'Connor: Introduction to Symbolic Logic who refer to it as the stroke function
$p \mathop {\bar \curlywedge} q$ Charles Sanders Peirce Modified Ampheck

The all-uppercase rendition NAND originates from the digital electronics industry, where, because NAND is Functionally Complete, this operator has a high importance.