(^^^) :: Int -> Int -> Int
-- testing 360 combinations of argument values
-- pruning with 56/91 rules
-- looking through 4 candidates of size 1
-- looking through 16 candidates of size 2
-- looking through 40 candidates of size 3
-- tested 37 candidates
0 ^^^ x  =  x
x ^^^ 0  =  x
x ^^^ y  =  0

(^^^) :: Int -> Int -> Int
-- testing 360 combinations of argument values
-- pruning with 56/91 rules
-- looking through 4 candidates of size 1
-- looking through 0 candidates of size 2
-- looking through 9 candidates of size 3
-- looking through 0 candidates of size 4
-- looking through 39 candidates of size 5
-- looking through 60 candidates of size 6
-- looking through 225 candidates of size 7
-- looking through 1056 candidates of size 8
-- looking through 1488 candidates of size 9
-- looking through 13020 candidates of size 10
-- tested 7148 candidates
x ^^^ y  =  if 0 == x * y
            then x + y
            else 0