{motive : Lean.Elab.Tactic.ElabSimpArgResult → Sort u} →
  (t : Lean.Elab.Tactic.ElabSimpArgResult) →
    t.ctorIdx = 2 →
      ((fvarId : Lean.FVarId) → motive (Lean.Elab.Tactic.ElabSimpArgResult.addLetToUnfold fvarId)) → motive t