I'm looking at the tutorial <http://haskell.org/haskellwiki/How_to_write_a_Haskell_program>

```
import System.Environment

main :: IO ()
main = getArgs >>= print . haqify . head

haqify s = "Haq! " ++ s

```

When running this program under HLint it gives the following error;

```
./Haq.hs:11:1: Warning: Eta reduce
Found:
  haqify s = "Haq! " ++ s
Why not:
  haqify = ("Haq! " ++ )

```

Can someone shed some light on what exactly **"Eta Reduce"** means in this context?