List.rev_go_twice: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/proofs/lib/list.bend as List
Lines 151-157 of bend-collections-laws-math@1.0.0.0/proofs/lib/list.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/proofs/lib/list.bend&start_line=151&end_line=157

import Base
import bend-collections-laws-math@1.0.0.0/spec/lib/common.bend as SC

# reverse.go(reverse.go(xs, a), b) == reverse.go(a, xs ++ b)
def rev_go_twice(-A: Data, +xs: List<&2, A>, +a: List<&2, A>, +b: List<&2, A>) -> {List.reverse.go(&2, A, List.reverse.go(&2, A, xs, a), b) == List.reverse.go(&2, A, a, SC.append(A, xs, b)) : List<&2, A>}:
  match xs:
    case Nil{}:
      {==}
    case Con{+h, +t}:
      rev_go_twice(A, t, Con{h, a}, b)

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.reverse.go
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/spec/lib/common.bend&name=append