;;; MODULAR-TRACE (plist modulus)                                    [FUNCTION]
;;;    Return PLIST with coefficients reduced modulo prime MODULUS.
;;;
;;; MODULAR-TRACE-1 (p modulus)                                      [FUNCTION]
;;;    Return a polynomial P with coefficients reduced modulo prime MODULUS.
;;;
;;; FROBENIUS-KERNEL (n modulus)                                     [FUNCTION]
;;;    Return a list of N polynomials of the form XI**MODULUS-XI, where
;;;    XI is the I-th variable. Work in internal alist representation.
;;;