{motive : Lean.Elab.Term.LetConfig → Sort u} →
  ((nondep usedOnly zeta postponeValue generalize : Bool) →
      (eq? : Option Lean.Ident) →
        motive
          { nondep := nondep, usedOnly := usedOnly, zeta := zeta, postponeValue := postponeValue,
            generalize := generalize, eq? := eq? }) →
    (t : Lean.Elab.Term.LetConfig) → motive t