{ρ : Type} →
  {pat : ρ} →
    [inst : String.Slice.Pattern.Model.ForwardPatternModel pat] →
      {s : String.Slice} →
        {motive :
            (a : s.Pos) →
              (a_1 : List (String.Slice.Pattern.SearchStep s)) →
                String.Slice.Pattern.Model.IsValidSearchFrom pat a a_1 → Prop} →
          {a : s.Pos} →
            {a_1 : List (String.Slice.Pattern.SearchStep s)} →
              String.Slice.Pattern.Model.IsValidSearchFrom pat a a_1 → Prop