empty space sensitivity in Try It! section

I've noticed that the validator seems very picky about spaces in my code. I'm extremely new to haskell and this could just be my own naivety. But for example,

``` haskell
let (_,(a:_)) = (10,"abc") in a
-- no spaces
```

validates and prompts the next lesson, whereas

``` haskell
let (_,(a:_)) = (10, "abc") in a
-- spaces
```

returns the correct value, but doesn't pass the test.
