week2.hs

:t True
True :: Bool

:t 1
1 :: Num a => a

:t [(1.2, "b", 'c'), (2.3, "d", 'e')]
[(1.2,"b",'c'),(2.3,"d",'e')] :: Fractional a => [(a,[Char],Char)]

inc :: Num a => a -> a
inc = (+) 1
map inc [1,2,3,4]

if 1 == 2 then True else False

signum n  | n > 0     = 1
          | n == 0    = 0
          | otherwise = -1

True && b = b
False && _ = False

1:2:3:[] == [1,2,3]

head :: [a] -> a
head (x:_) = x

second :: [a] -> a
second (_:x:_) = x

map (\x -> x + 1) [1,2,3,4]

1+ 2
(+) 1 2
(1+) 2
(+2) 1