%mathpiper,def="IsNegativeNumber"

IsNegativeNumber(x):= IsNumber(x) And x < 0;

%/mathpiper



%mathpiper_docs,name="IsNegativeNumber",categories="User Functions;Predicates"
*CMD IsNegativeNumber --- test for a negative number
*STD
*CALL
	IsNegativeNumber(n)

*PARMS

{n} -- number to test

*DESC

{IsNegativeNumber(n)} evaluates to {True} if $n$ is (strictly) negative, i.e.
if $n<0$. If {n} is not a number, the functions return {False}. 

*E.G.

In> IsNegativeNumber(6);
Result: False;
In> IsNegativeNumber(-2.5);
Result: True;

*SEE IsNumber, IsPositiveNumber, IsNotZero, IsNegativeInteger, IsNegativeReal
%/mathpiper_docs