and :: [Bool] -> Bool
-- testing 14 combinations of argument values
-- looking through 2/12 candidates of size 1
-- looking through 3/12 candidates of size 2
-- looking through 6/25 candidates of size 3
-- looking through 6/48 candidates of size 4
-- looking through 16/84 candidates of size 5
-- looking through 41/185 candidates of size 6
-- looking through 103/447 candidates of size 7
-- looking through 278/1123 candidates of size 8
-- looking through 752/2982 candidates of size 9
and ps  =  null ps || head ps && and (tail ps)

or :: [Bool] -> Bool
-- testing 14 combinations of argument values
-- looking through 2/12 candidates of size 1
-- looking through 3/12 candidates of size 2
-- looking through 6/25 candidates of size 3
-- looking through 6/48 candidates of size 4
-- looking through 16/84 candidates of size 5
-- looking through 41/185 candidates of size 6
-- looking through 103/447 candidates of size 7
-- looking through 278/1123 candidates of size 8
-- looking through 752/2982 candidates of size 9
-- looking through 1963/7993 candidates of size 10
-- looking through 5427/21497 candidates of size 11
or ps  =  not (null ps || not (head ps || or (tail ps)))

and :: [Bool] -> Bool
-- testing 14 combinations of argument values
-- looking through 2/13 candidates of size 1
-- looking through 3/14 candidates of size 2
-- looking through 6/31 candidates of size 3
-- looking through 8/63 candidates of size 4
and ps  =  foldr (&&) True ps

or :: [Bool] -> Bool
-- testing 14 combinations of argument values
-- looking through 2/13 candidates of size 1
-- looking through 3/14 candidates of size 2
-- looking through 6/31 candidates of size 3
-- looking through 8/63 candidates of size 4
or ps  =  foldr (||) False ps