I have two arrays: a1 and a2. Assuming a1 is smaller than a2, how do I verify if a1 is part of a2?

For example: if a1 is [1|3|8|7] and a2 is [5|6|1|3|8|7|3|3|4], the answer to the verification will be yes because a2 contains the sequence ...1|3|8|7... which is the a1 array