# not -- negation

## Description

not x -- yields the negation of x, which must be true or false.

• and -- conjunction
• or -- disjunction

## Ways to use symbol not :

• not Equation (missing documentation)

## For the programmer

The object not is .

This operator may be used as a prefix unary operator in an expression like not y. The user may install a method for handling such expressions with code such as

            not  Y := (y) -> ...

where Y is the class of y.