def b_cg_base

bendtorch@1.3.0.0 · PROOF.bend:623

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

623def b_cg_base(-k: Nat, xs: List<&1, T.BG>, -acc: List<&1, T.BG>, e: {T.cut(T.BG, k, xs, acc) == T.Halves{List.reverse(&1, T.BG, acc), xs} : T.Halves<T.BG>}, r: b_GAR<acc, Nil{}, xs>) -> b_CGR<k, xs, acc>:
624  match r:
625    case b_GAR{ys, +same, fact}:
626      b_CGR{T.Halves{List.reverse(&1, T.BG, ys), xs},
627        Equal.trans(T.Halves<T.BG>, T.Halves{List.reverse(&1, T.BG, ys), xs}, T.Halves{List.reverse(&1, T.BG, acc), xs}, T.cut(T.BG, k, xs, acc), Equal.cong(List<&1, T.BG>, T.Halves<T.BG>, z => T.Halves{List.reverse(&1, T.BG, z), xs}, ys, acc, same), Equal.sym(T.Halves<T.BG>, T.cut(T.BG, k, xs, acc), T.Halves{List.reverse(&1, T.BG, acc), xs}, e)),
628        Equal.trans(List<&1, T.BG>, List.append(&1, T.BG, List.reverse.go(&1, T.BG, ys, Nil{}), xs), List.append(&1, T.BG, List.reverse.go(&1, T.BG, acc, Nil{}), xs), List.reverse.go(&1, T.BG, acc, xs), Equal.cong(List<&1, T.BG>, List<&1, T.BG>, z => List.append(&1, T.BG, List.reverse.go(&1, T.BG, z, Nil{}), xs), ys, acc, same), fact)}