Q:

V4/V13 support lib : Fragment work, ViewPager does not?

Testing other components in android support library, 
On device classLoader can't find ViewPager however it can find other support components FragmentActivity, Fragments etc . ( using V4 as well as V13, gives same result)
What's special with ViewPager ? Does it depends on another support components to work ? (Like Fragment needs FragmentActivity)
NOTE: I think I'm properly exporting support library as dependency, else Fragment would also not have worked.

A:

You should reference it like this:
<android.support.v4.view.ViewPager
    android:id="@+id/pager"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />

<v4support:ViewPager> is not correct. you need the whole package name in the xml.

