theorem String.Slice.Pattern.Model.split_char_eq_split_beq {c : Char} {s : Slice} (f curr : s.Pos) (hle : f ≤ curr) :
theorem String.Slice.toList_splitToSubslice_char {s : Slice} {c : Char} :
List.map (copy ∘ Subslice.toSlice) (s.splitToSubslice c).toList = List.map ofList (List.splitOn c s.copy.toList)