from typing import Sequence


def contains(a: Sequence, b: Sequence) -> bool:
    """
    Determines if a sequence contains a subsequence.
    """
    # If we needed to deal with larger inputs, this could be smarter.
    return any(
        all(a[a_i + b_i] == b[b_i] for b_i in range(len(b)))
        for a_i in range(len(a) - len(b) + 1)
    )