Point.decompress: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/src/crypto/secp256k1/point.bend as Point
Lines 174-176 of bend-collections@1.0.0.0/src/crypto/secp256k1/point.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/point.bend&start_line=174&end_line=176

import Base
import bend-collections@1.0.0.0/src/crypto/secp256k1/field.bend as F

def decompress(+x: List<&2, Nat>, +par: Nat) -> Maybe<&2, Point>:
  +y = F.sqrt(rhs(x))
  decompress_if(x, lift_y(y, par), F.eq(F.sq(y), rhs(x)))

Uses (10):
  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=Nat
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/field.bend&name=eq
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/field.bend&name=sq
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/field.bend&name=sqrt
  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/point.bend&name=decompress_if
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/point.bend&name=lift_y
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/secp256k1/point.bend&name=rhs