Random.Perm.permutation: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/spec/math/random.bend as Random
Lines 116-117 of bend-collections-laws-math@1.0.0.0/spec/math/random.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/spec/math/random.bend&start_line=116&end_line=117

import Base
import bend-collections-laws-math@1.0.0.0/src/math/u64.bend as W
import bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend as R
import bend-collections-laws-math@1.0.0.0/spec/math/random/rand.bend as SR

def Perm.permutation(~S: Data, ~next: S -> W.U64 & S, +s: S, +n: Nat, +i: Nat) -> Type:
  {SR.occurrences(~Nat, ~Nat, ~Nat.is_eq, i, R.fst(List<&2, Nat>, S, R.perm(~S, ~next, s, n))) == SR.b2n(Nat.is_lt(i, n)) : Nat}

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=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_eq
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/spec/math/random/rand.bend&name=b2n
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/spec/math/random/rand.bend&name=occurrences
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend&name=fst
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/random/rand.bend&name=perm
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/u64.bend&name=U64