class prep_PP_modifier
{
         %% a PP may post modify another PP to form a range: de X à Y, de X en Y
         %% the construction should not be iterated
         %% and should be restricted to component of same nature
         %% we only assume both parts of the range are of the same category
         %% other soft constraints (such as a same lemma, entities, ...) may be
         %% checked at disamb time
         %% it seems to exists some similarities with coordinations (de chex X à chez Y )
    <: _prep_modifier;
    PP < Foot;
    node(Root).cat = value(PP);
    node(Anchor).bot.pcas = value(de);
    node(Foot).bot.pcas = value(à|en|vers);
    node(Foot).bot.real = node(PP).bot.real;
    desc.dependency = value(range);
}