def not_(arg):
    """:yaql:operator not

    Returns true if arg evaluates to false. Otherwise returns false.

    :signature: not arg
    :arg arg: value to be converted
    :argType arg: any
    :returnType: boolean

    .. code::

        yaql> not true
        false
        yaql> not {}
        true
        yaql> not [1]
        false
    """
    return not arg