<w> inside of <w> is invalid
http://thread.gmane.org/gmane.comp.literature.sword.devel/28369/focus=28373 So,
<w morph="robinson:V-2RAI-3S">
<w type="x-spoj">jsou</w>
</w>
is invalid OSIS, so I have to merge it somehow into
<w type="x-spoj" morph="robinson:V-2RAI-3S">jsou</w>