{motive : Lean.Meta.Ext.ExtTheorem → Sort u} →
  (t : Lean.Meta.Ext.ExtTheorem) →
    ((declName : Lean.Name) →
        (priority : ℕ) →
          (keys : Array Lean.Meta.DiscrTree.Key) →
            motive { declName := declName, priority := priority, keys := keys }) →
      motive t