∀ (lhs : Bool) (s : Lean.Grind.AC.Seq) (c₁ : Lean.Meta.Grind.AC.EqCnstr) (c₂ : Lean.Meta.Grind.AC.DiseqCnstr),
  sizeOf (Lean.Meta.Grind.AC.DiseqCnstrProof.simp_prefix lhs s c₁ c₂) =
    1 + sizeOf lhs + sizeOf s + sizeOf c₁ + sizeOf c₂