# Definition:Logical NOR/Truth Function

The NOR connective defines the truth function $f^\downarrow$ as follows:
 $\ds \map {f^\downarrow} {\F, \F}$ $=$ $\ds \T$ $\ds \map {f^\downarrow} {\F, \T}$ $=$ $\ds \F$ $\ds \map {f^\downarrow} {\T, \F}$ $=$ $\ds \F$ $\ds \map {f^\downarrow} {\T, \T}$ $=$ $\ds \F$