∀ {pu : Lean.Compiler.LCNF.Purity} (n offset : ℕ) (var : Lean.FVarId)
  (h : autoParam (pu = Lean.Compiler.LCNF.Purity.impure) Lean.Compiler.LCNF.LetValue._auto_11),
  sizeOf (Lean.Compiler.LCNF.LetValue.sproj n offset var h) = 1 + sizeOf n + sizeOf offset + sizeOf var + sizeOf h