Test for array slice?

Hi-

I want to do something like this (pardon my pseudocode):

A=ARRAY[4, 5, 6, 7, 8]
B=ARRAY[5, 6]

is_sliceof(A, B), i.e., there exists a slice of A that equals B.  My
best thought ATM is to convert both to strings and use pattern matching
- any better ideas?

--Pete