∀ (ref : Lean.Syntax) («meta» : Bool) (discr : Lean.Syntax)
  (alts : Array (Lean.Elab.Term.Do.AltExpr Lean.Elab.Term.Do.Code)) (elseBranch : Lean.Elab.Term.Do.Code),
  sizeOf (Lean.Elab.Term.Do.Code.matchExpr ref «meta» discr alts elseBranch) =
    1 + sizeOf ref + sizeOf «meta» + sizeOf discr + sizeOf alts + sizeOf elseBranch