Test if curve parameters are valid.
(weierstrass-elliptic-curve-p p a b) tests whether the Short Weierstrass curve defined byFunction:
(defun weierstrass-elliptic-curve-p (p a b) (and (dm::primep p) (< 3 p) (fep a p) (fep b p) (posp (mod (+ (* 4 a a a) (* 27 b b)) p))))