Schnorr.verify_p: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/src/crypto/secp256k1/schnorr.bend as Schnorr
Lines 61-69 of bend-collections@1.0.0.0/src/crypto/secp256k1/schnorr.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/schnorr.bend&start_line=61&end_line=69

import Base
import bend-collections@1.0.0.0/src/crypto/secp256k1/field.bend as F
import bend-collections@1.0.0.0/src/crypto/secp256k1/scalar.bend as S
import bend-collections@1.0.0.0/src/crypto/secp256k1/point.bend as P
import bend-collections@1.0.0.0/src/crypto/secp256k1/bytes.bend as B

def verify_p(+pk: List<&2, U32>, +m: List<&2, U32>, +sig: List<&2, U32>, mp: Maybe<&2, P.Point>) -> Bool:
  match mp:
    case None{}: False{}
    case Some{+pp}:
      +rb = B.prefix(32n, sig)
      +r = B.of_be(rb)
      +s = B.of_be(B.suffix(32n, sig))
      +e = S.reduce(B.of_be(tagged(tag_challenge(), cat(rb, cat(pk, m)))))
      verify_ok(r, s, e, pp, Bool.and(F.lt_p(r), S.lt_n(s)))

Uses (16):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/bytes.bend&name=of_be
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/bytes.bend&name=prefix
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/bytes.bend&name=suffix
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/field.bend&name=lt_p
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/point.bend&name=Point
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/scalar.bend&name=lt_n
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/scalar.bend&name=reduce
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/schnorr.bend&name=cat
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/schnorr.bend&name=tag_challenge
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/schnorr.bend&name=tagged
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/schnorr.bend&name=verify_ok