functional programming in haskell

6. (a) What is the type of the following unknown7 function? Give the most general type and include any required class constraints.

> unknown7 xs = all (\(x,y) -> (x<=y)) (zip xs (tail xs))

(b) Give a description of what the unknown7 function in part (a) does. Describe what it does, not how it works.

(c) Give a non-trivial test case for the unknown7 function in part (a) and show the expected results.