∀ (ka : ℤ) (ca? : Option Lean.Meta.Grind.Arith.Cutsat.EqCnstr) (kb : ℕ)
  (cb? : Option Lean.Meta.Grind.Arith.Cutsat.EqCnstr),
  sizeOf (Lean.Meta.Grind.Arith.Cutsat.EqCnstrProof.pow ka ca? kb cb?) =
    1 + sizeOf ka + sizeOf ca? + sizeOf kb + sizeOf cb?