{motive : Lean.Elab.Tactic.Do.ExceptCondsDefault✝ → Sort u} →
  (ctorIdx : ℕ) →
    (t : Lean.Elab.Tactic.Do.ExceptCondsDefault✝¹) →
      ctorIdx = Lean.Elab.Tactic.Do.ExceptCondsDefault.ctorIdx✝ t →
        Lean.Elab.Tactic.Do.ExceptCondsDefault.ctorElimType✝ ctorIdx → motive t