Type Alias NarrowedBy<T, Pat, Depth>

NarrowedBy: Pat extends PPattern
    ? NarrowByPTag<T, Pat, Depth>
    : Pat extends readonly (infer U)[]
        ? Extract<T, U>
        : Pat extends object
            ? ObjectNarrow<T, Pat, Prev[Depth]>
            : Pat extends T ? Pat : never