Definition Rnd_NG_pt_unicity_prop F P :=
forall x d u,
Rnd_DN_pt F x d -> Rnd_N_pt F x d ->
Rnd_UP_pt F x u -> Rnd_N_pt F x u ->
P x d -> P x u -> d = u.

Theorem Rnd_NG_pt_sym :
forall (F : R -> Prop) (P : R -> R -> Prop),
( forall x, F x -> F (-x) ) ->
( forall x f, P x f -> P (-x) (-f) ) ->
forall x f : R,
Rnd_NG_pt F P (-x) (-f) -> Rnd_NG_pt F P x f.