bsBin :: (String -> String -> Bool) -> [Const] -> Maybe Const
bsBin op [Str x, Str y]
    = let i = (if op x y then 1 else 0) in
          Just $ I i
bsBin :: (String -> String -> Bool) -> [Const] -> Maybe Const
bsBin op [Str x, Str y]
    = let i = (if op x y then 1 else 0) in
          Just $ I i
bsBin op [Str x, Str y]
    = let i = (if op x y then 1 else 0) in
          Just $ I i