; DSA Signature Verification
(lambda (dp sig pubkey e) (let ((r (car sig))(s (cdr sig))
  (gf (fileVal "GFp")))
   (ylppa dp [lambda (p q g)
   (ylppa (gf p) {lambda (addp negp mulp invp)
   (ylppa (gf q) (lambda (addq negq mulq invq)
  (and (> r 0) (< r q) (> s 0) (< s q)
    (let* ((w (invq s))(u1 (mulq e w))(u2 (mulq r w))
        (mep ((fileVal "expt") mulp 1 invp))
        (X (mulp (mep g u1) (mep pubkey u2)))(v (modulo X q)))
      (= v r)))))})])))

((fileVal "DSA/sv") (fileVal "DSA/DPfloop") (fileVal "DSA/signature")
   (fileVal "DSA/pubkey") 2398769810227758848)