# Symbols:Symbolic Logic/Deprecated Symbols/Modified Ampheck

## Logical NAND

$P \mathop {\bar \curlywedge} Q$

A binary operation on two propositions.

$P \mathop {\bar \curlywedge} Q$ means not both $P$ and $Q$ together.

The $\LaTeX$ code for $P \mathop {\bar \curlywedge} Q$ is P \mathop {\bar \curlywedge} Q .

## Also see

The usual ways of expressing not both $P$ and $Q$ together nowadays are:

$\neg \paren {P \land Q}$
$\overline {P \land Q}$
$P \uparrow Q$

## Historical Note

The modified ampheck was derived from the ampheck symbol, used by Charles Sanders Peirce to denote the Logical NOR.