(** From this general result, we now describe particular cases of [compare_cont p q c = c'] : - When [c=Eq], this is directly [compare] - When [c<>Eq], we'll show first that [c'<>Eq] - That leaves only 4 lemmas for [c] and [c'] being [Lt] or [Gt] *)

Lemma compare_cont_Lt_not_Gt p q :
compare_cont Lt p q <> Gt <-> p <= q.