class impersonal_subject
{
    %% impersonal subject before verbs
    node imp_subj_alt : [type: alternative];
    % ilimp is not perfect
    % => need to keep the 'il' node
    %%    imp_subj_alt >> il;         
    imp_subj_alt >> ilimp;
    imp_subj_alt >> caimp;
    %%    il < ilimp;
    ilimp < caimp;
%%    node il : [type: coanchor, id:impsubj, adj: no, cat: cln, lex: il];
    node ilimp : [type: coanchor, id:impsubj, adj: no, cat: ilimp];
    node caimp : [type: coanchor, id:impsubj, adj: no, cat: caimp];
    - imp_subj_alt::agreement; imp_subj_alt = imp_subj_alt::N;
%%    - il::agreement; il = il::N;
    - ilimp::agreement; ilimp = ilimp::N;
    - caimp::agreement; caimp = caimp::N;
    imp_subj_alt =>
        desc.ht.imp = value(+),
        desc.extraction = value(~topic),
        desc.dummy.impsubj = value(+),
        node(S).bot.number=value(sg),
        node(S).bot.person=value(3)
        ;
    ~ imp_subj_alt =>
        desc.dummy.impsubj = value(~+)
        ;
}