b. (20 point) Write a function isSimple, in Haskell, it will take
a list lst (of type [(Prin,a)]) as input, return true if the first
coordinate of each tuple in lst is a simple principal. Otherwise
it will return False.

test2b1 :: Bool
test2b1 = isSimple [(y,1),(m,2),(h,3)]

test2b2 :: Bool
test2b2 = isSimple [((Quote y m) , 1) ,(m,2), (h,3)]

We have

*Main> test2b1
True
*Main> test2b2
False