F#: Exercise 2.3 Write a function combinePair : int list -> (int*int) list so that combinePair xs returns the list with elements from xs combined into pairs. If xs contains an odd number of elements, then the last element is thrown away: combinePair [x1; x2; x3; x4] = [(x1,x2);(x3,x4)] combinePair [x1; x2; x3] = [(x1,x2)] combinePair [] = [] combinePair [x1] = [].

Hint: use pattern matching