def rev_none

bend-collections-laws-math@1.0.0.0 · proofs/math/typed/fixbytes.bend:156

import Base
import bend-collections-laws-math@1.0.0.0/spec/lib/common.bend as C
import bend-collections-laws-math@1.0.0.0/spec/math/fixed.bend as SF
import bend-collections-laws-math@1.0.0.0/proofs/lib/list.bend as LL

156def rev_none(+k: Nat, +xs: List<&2, Nat>, +h: {Nat.is_eq(C.length(Nat, xs), k) == False{} : Bool}) -> {SF.from_le(k, C.reverse(Nat, xs)) == None{} : Maybe<&2, Nat>}:
157  fl_len(k, C.reverse(Nat, xs), Equal.trans(Bool, Nat.is_eq(C.length(Nat, C.reverse(Nat, xs)), k), Nat.is_eq(C.length(Nat, xs), k), False{}, Equal.cong(Nat, Bool, t => Nat.is_eq(t, k), C.length(Nat, C.reverse(Nat, xs)), C.length(Nat, xs), LL.length_rev(Nat, xs)), h))