1 files changed, 31 insertions, 0 deletions
diff --git a/46-50/47.hs b/46-50/47.hs
new file mode 100644
index 0000000..f672f4a
--- /dev/null
+++ b/46-50/47.hs
@@ -0,0 +1,31 @@
+and', or', nand', nor', xor', impl', equ' :: Bool -> Bool -> Bool
+not' :: Bool -> Bool
+
+not' True = False
+not' False = True
+
+and' True True = True
+and' _ _ = False
+
+or' False False = False
+or' _ _ = True
+
+xor' True False = True
+xor' False True = True
+xor' _ _ = False
+
+equ' a b = (not' a) `xor'` b
+impl' a b = (not' a) `or'` b
+
+nand' a = not' . and' a
+nor' a = not' . or' a
+
+table2 :: (Bool -> Bool -> Bool) -> IO ()
+table2 f = mapM_ putStrLn [show a ++ " " ++ show b ++ " " ++ (show $ f a b)
+                            | let bin = [True, False], a <- bin, b <- bin]
+
+infixl 4 `or'`
+infixl 5 `xor'`
+infixl 6 `and'`
+infixl 7 `equ'`
+-- use not for negation, it has fixity 9 by default