∀ {pat : ByteArray} {stackPos : ℕ} {hst : stackPos < pat.size} {guess : ℕ} {hg : guess < stackPos},
  String.Slice.Pattern.Model.ForwardSliceSearcher.prefixFunction✝ pat stackPos hst ≤ guess + 1 →
    String.Slice.Pattern.Model.ForwardSliceSearcher.PartialMatch✝ pat pat guess stackPos →
      String.Slice.Pattern.Model.ForwardSliceSearcher.prefixFunctionRecurrence✝ pat stackPos hst guess hg =
        String.Slice.Pattern.Model.ForwardSliceSearcher.prefixFunction✝¹ pat stackPos hst