Elsewhere on the avant-garde front, Numero Deux, by Jean-Luc Godard, will have its overdue American premiere June 19 at the Carnegie Hall Cinema in New York opening a new International Film Theater series. An enormously complicated meditation on the family unit, shot on videotape and transferred to film, "Numero Deux" is more tentative and less accessible than Godard's recent art-theater hit, "Every Man for Himself." Yet it shows Godard at the peak of his powers when it comes to boldness and invention, if not coherence. Once a young rebel, he has matured into -- well, a mature rebel. However one reacts to his work, there's not an ounce of complacency in it. And that's cause for rejoicing , as ever.