Shuffle.swap_occ: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/proofs/math/random/shuffle.bend as Shuffle
Lines 96-98 of bend-collections-laws-crypto@1.0.0.0/proofs/math/random/shuffle.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/math/random/shuffle.bend&start_line=96&end_line=98

import Base
import bend-collections-laws-crypto@1.0.0.0/src/math/random/rand.bend as R

# THEOREM: a swap keeps every count
def swap_occ(~A: Data, ~V: Data, ~rel: A -> V -> Bool, +v: V, +xs: List<&2, A>, +i: Nat, +j: Nat) -> {occ(~A, ~V, ~rel, v, R.swap(A, xs, i, j)) == occ(~A, ~V, ~rel, v, xs) : Nat}:
  swap_m_occ(~A, ~V, ~rel, v, xs, i, j, R.nth(A, xs, i), R.nth(A, xs, j), {==}, {==})

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  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=bend-collections-laws-crypto@1.0.0.0/proofs/math/random/shuffle.bend&name=occ
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/math/random/shuffle.bend&name=swap_m_occ
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/random/rand.bend&name=nth
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/random/rand.bend&name=swap