minusp real → generalized-boolean

plusp real → generalized-boolean

real — a real.

generalized-boolean — a generalized boolean.

minusp returns true if real is less than zero; otherwise, returns false.

plusp returns true if real is greater than zero; otherwise, returns false.

Regardless of whether an implementation provides distinct representations for positive and negative float zeros, (minusp -0.0) always returns false.

(minusp -1) → true 
(plusp 0) → false 
(plusp least-positive-single-float) → true

Should signal an error of type type-error if real is not a real.