file structure (hierarchy)

[Werner]

Hello, 

I've written a file containing a score with a structure like:

\score {
  \new Staff = bla <<
    \new voice =blu {\voiceOne \Sopran}
    \new voice =blu {\voiceTwo \Alt} >>
}

Wanted to put the 
\set Score.skipBars = ##t
command in.

This: 

\score {
  \new Staff = bla <<
    \new voice =blu {\voiceOne \Sopran}
    \new voice =blu {\voiceTwo \Alt} >>
\set Score.skipBars = ##t
}

brings syntax error unexpected \set

This

\score {
  \new Staff = bla <<
    \new voice =blu {\voiceOne \Sopran}
    \new voice =blu {\voiceTwo \Alt}
\set Score.skipBars = ##t >>
}

works.

For me this is very strange.
Also the documentation gives no hint about...
Could somebody explain that?

WM