The issues were explained on this and the other threads about Breivik, he serves the sentence of 21 years and is subject to "Forvaring." Just like any other murderer who is sentenced, they still have to go before a Parole Board.
I was personally shocked until I read up on Norway's system. It might help you to stop sounding so shrill if you did the same. As for your comments elsewhere about the European Court of Justice - Norway is not part of the EU, the only European body that has say in Norwegian Law is EFTA and that has to do with disputes between member and non-member countries and it also looks at trade.
Anyhow, as others have explained to you is that Brievik isn't going anywhere soon.
Crown Prosecution Service Guidelines.
The rest of the page details different degrees of classification - it recognises the difference between aggravating factors and mitigating factors. In the case of mitigating factors, Lord Woolf advised in 2004 that a confessing murderer at the lower end of the scale could reduce his or her sentence by early confession so in theory someone at the lighter end could reduce their 12-16 year minimum sentence. However it is still down to a Parole Board to decide whether a convicted felon was ready for release.
Life sentences are still given in the category of
exceptionally high seriousness such as that of David Tiley in 2007. He will never come before a Parole Board.
This stopped with the 2003 Act. The Home Secretary has no say in sentences anymore.