[Haskell-beginners] quickCheck generation question

I'm going through the 99 Haskell problems and am trying to write quickCheck properties for each one. -- 3 (find k"th element of a list) element_at xs x = xs !! x prop_3a xs x = (x < length xs && x >= 0) ==> element_at xs (x::Int) == (xs !! x::Int) When I run prop_3a through quickCheck, it gives up, saying that it only passed 1 test. This makes sense, because the random x is going to be larger than the number of elements in the random list in most cases. So what I need to do is write a generator that generates a random list with length larger than a random integer, but I'm not sure how to do that. Thanks! Joe