Nand

is a dyadic scalar boolean function which tests if either argument is not true: it returns 0 if both are 1 and 1 if at least one is 0. It represents the Sheffer stroke or alternative denial in Boolean logic. Nand is the boolean negation  of the And function , and so its glyph is composed from those. However, fonts vary in how they compose them; some overlaying the glyphs (∧&#x334;), and some stacking them (∧&#x303;).

Examples
The following shows all possible combinations of inputs as a Boolean function.

Documentation

 * Dyalog
 * APLX
 * J Dictionary, NuVoc