Nor

is a dyadic scalar boolean function which tests if neither argument is true: it returns 1 if both are 0 and 0 if at least one is 1. It represents Peirce's arrow or joint denial in Boolean logic. Nor is the boolean negation  of the Or 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