def cg_base

bendtorch@1.3.0.0 · PROOF.bend:348

import Base
import bendtorch@1.3.0.0/main.bend as T

348def cg_base(-k: Nat, xs: List<&1, T.FS>, -acc: List<&1, T.FS>, e: {T.cut(T.FS, k, xs, acc) == T.Halves{List.reverse(&1, T.FS, acc), xs} : T.Halves<T.FS>}, r: GAR<acc, Nil{}, xs>) -> CGR<k, xs, acc>:
349  match r:
350    case GAR{ys, +same, fact}:
351      CGR{T.Halves{List.reverse(&1, T.FS, ys), xs},
352        Equal.trans(T.Halves<T.FS>, T.Halves{List.reverse(&1, T.FS, ys), xs}, T.Halves{List.reverse(&1, T.FS, acc), xs}, T.cut(T.FS, k, xs, acc), Equal.cong(List<&1, T.FS>, T.Halves<T.FS>, z => T.Halves{List.reverse(&1, T.FS, z), xs}, ys, acc, same), Equal.sym(T.Halves<T.FS>, T.cut(T.FS, k, xs, acc), T.Halves{List.reverse(&1, T.FS, acc), xs}, e)),
353        Equal.trans(List<&1, T.FS>, List.append(&1, T.FS, List.reverse.go(&1, T.FS, ys, Nil{}), xs), List.append(&1, T.FS, List.reverse.go(&1, T.FS, acc, Nil{}), xs), List.reverse.go(&1, T.FS, acc, xs), Equal.cong(List<&1, T.FS>, List<&1, T.FS>, z => List.append(&1, T.FS, List.reverse.go(&1, T.FS, z, Nil{}), xs), ys, acc, same), fact)}