at least as ... asUsually appears in the fixed expression 勝るとも劣らず or 勝るとも劣らぬ, meaning that something is no less than or at least equal to something else. This is formal or literary language.
JA: この店の料理は有名店にも勝るとも劣らない。
EN: The food at this restaurant is at least as good as that at famous restaurants.