Back key behavior after up action
<p>Here <a href="http://developer.android.com/design/patterns/navigation.html" rel="nofollow">http://developer.android.com/design/patterns/navigation.html</a> is some tips about <strong>back</strong> and <strong>up</strong> navigation. It's quite clear what does <strong>up</strong> do on <a href="http://developer.android.com/design/media/navigation_between_siblings_market1.png" rel="nofollow">this example</a>, it closes those activities. </p>

<p>But what happen <a href="http://developer.android.com/design/media/navigation_between_siblings_market2.png" rel="nofollow">here</a>? I go to the market, open book, then another one, then open movie, and then I decide to press <strong>up</strong> to go to movies category.<br>
What has happened to books activities?<br>
Can I somehow go to them?<br>
Where do I go when I click back button, to the market?</p>
