intro n; case n.
intros.
simpl in |- *.
red in |- *.
intro.
inversion x.
inversion in_range_prf.
intros.
elim (lin_dep_defs_eqv (seq_set v)).
intros.
generalize (H2 H0); clear H3 H2 H0.
intro.
unfold lin_indep' in H0.
generalize (H0 _ a (seq_set_seq v)).
intro; clear H0.
cut (distinct (seq_set_seq v)); auto.
intro.
generalize (H2 H0).
clear H2 H0.
intro.
apply NNPP.
unfold not in |- *; intros.
unfold not in H0.
apply H0.
auto.
apply Trans with (sum (mult_by_scalars a v)); auto with algebra.
Qed.

(* Specifications: *)
Lemma lin_indep_doesn't_contain_zero :
forall X : part_set V, lin_indep X -> ~ in_part (zero V) X.