functional programming in haskell

2. (a) What is the type of the following unknown3 function? Give the most general type and include any required class constraints to the best of your understanding.

> unknown3 xs = \ys -> [(x,y) | x <- xs, y <- ys, x < y ]

(b) Give a simple description of what the unknown3 function in part (a) does. Describe what it does, not how it works.

(c) Give a non-trivial test case of the function unknown3 and show the expected results.