test whether a number is negative
Major Section:  ACL2-BUILT-INS

(Minusp x) is true if and only if x < 0.

The guard of minusp requires its argument to be a rational (real, in ACL2(r)) number.

Minusp is a Common Lisp function. See any Common Lisp documentation for more information.

To see the ACL2 definition of this function, see pf.