Merge pull request #51 from noahlz/master

Fix issue #50

haskell.html.markdown

@@ -120,6 +120,10 @@ snd ("haskell", 1) -- 1
 -- A simple function that takes two variables
 add a b = a + b
 
+-- Note that if you are using ghci (the Haskell interpreter)
+-- You'll need to use `let`, i.e.
+-- let add a b = a + b
+
 -- Using the function
 add 1 2 -- 3