and :: [Bool] -> Bool
-- testing 14 combinations of argument values
-- looking through 2 candidates of size 1
-- looking through 2 candidates of size 2
-- looking through 4 candidates of size 3
-- looking through 4 candidates of size 4
-- looking through 6 candidates of size 5
-- looking through 15 candidates of size 6
-- looking through 37 candidates of size 7
-- looking through 88 candidates of size 8
-- looking through 200 candidates of size 9
-- looking through 464 candidates of size 10
and ps  =  if null ps then True else head ps && and (tail ps)

or :: [Bool] -> Bool
-- testing 14 combinations of argument values
-- looking through 2 candidates of size 1
-- looking through 2 candidates of size 2
-- looking through 4 candidates of size 3
-- looking through 4 candidates of size 4
-- looking through 6 candidates of size 5
-- looking through 15 candidates of size 6
-- looking through 37 candidates of size 7
-- looking through 88 candidates of size 8
-- looking through 200 candidates of size 9
-- looking through 464 candidates of size 10
or ps  =  if null ps then False else head ps || or (tail ps)

and :: [Bool] -> Bool
-- testing 14 combinations of argument values
-- looking through 2 candidates of size 1
-- looking through 2 candidates of size 2
-- looking through 4 candidates of size 3
-- looking through 6 candidates of size 4
and ps  =  foldr (&&) True ps

or :: [Bool] -> Bool
-- testing 14 combinations of argument values
-- looking through 2 candidates of size 1
-- looking through 2 candidates of size 2
-- looking through 4 candidates of size 3
-- looking through 6 candidates of size 4
or ps  =  foldr (||) False ps