class verb_extraction 
{
    <: _verb_extraction;
    desc.extraction = node(S2).top.extraction;
    node(S2).bot.extraction = node(S2).top.extraction;
%    node(S).bot.extraction = node(S2).top.extraction;
    node(S).bot.extraction = value(adjx|wh);
    node(S).top.extraction = value(adjx|estceaux);
}