(* partial version of compatible QI *)
Definition p_assignment_function := function -> option(list nat -> nat).
(* partial assignment of a term*)
Fixpoint p_term_assignment (qic:assignment_constructor) (qif:p_assignment_function)
(t:term) {struct t} : option nat:=
match t with
| var v=> Some 0 (* pas necessaire. Les QI sont toujours appliquées sur des termes clots. *)
| capply c lt => option_map (qic c) (option_list_map(map (p_term_assignment qic qif) lt))
| fapply f lt=> option_bind (fun g => option_map g (option_list_map(map (p_term_assignment qic qif)  lt)))
(qif f)
end.
Definition complete_p_QI (qif : p_assignment_function) f :=
complete_option maxl (qif f).

Lemma p_term_assignment_term_assignment qic qif t v:
p_term_assignment qic qif t = Some v ->
term_assignment qic (complete_p_QI qif) t = v.