odd :: Int -> Bool
-- testing 6 combinations of argument values
-- pruning with 21/44 rules
-- looking through 2 candidates of size 1
-- looking through 1 candidates of size 2
-- looking through 1 candidates of size 3
-- looking through 1 candidates of size 4
-- looking through 1 candidates of size 5
-- looking through 0 candidates of size 6
-- looking through 2 candidates of size 7
-- tested 8 candidates
odd 0  =  False
odd 1  =  True
odd x  =  odd (x - 2)

even :: Int -> Bool
-- testing 6 combinations of argument values
-- pruning with 21/44 rules
-- looking through 2 candidates of size 1
-- looking through 1 candidates of size 2
-- looking through 1 candidates of size 3
-- looking through 1 candidates of size 4
-- looking through 1 candidates of size 5
-- looking through 0 candidates of size 6
-- looking through 2 candidates of size 7
-- tested 8 candidates
even 0  =  True
even 1  =  False
even x  =  even (x - 2)

odd :: Int -> Bool
-- testing 6 combinations of argument values
-- pruning with 36/55 rules
-- looking through 0 candidates of size 1
-- looking through 0 candidates of size 2
-- looking through 3 candidates of size 3
-- looking through 1 candidates of size 4
-- looking through 46 candidates of size 5
-- tested 31 candidates
odd x  =  1 == x `mod` 2

even :: Int -> Bool
-- testing 6 combinations of argument values
-- pruning with 36/55 rules
-- looking through 0 candidates of size 1
-- looking through 0 candidates of size 2
-- looking through 3 candidates of size 3
-- looking through 2 candidates of size 4
-- looking through 45 candidates of size 5
-- tested 22 candidates
even x  =  0 == x `mod` 2