let define axdef =
F.add_declaration {
d_name = axdef.a_defname ;
d_section = S_User_Prop ;
d_title = (fun fmt -> pp_axiomdef_title fmt axdef) ;
d_descr = (fun fmt -> pp_axiomdef_descr fmt axdef) ;
d_source = None ;
d_item = Formula.Axiom axdef.a_property ;
}