With QUATRE UN we are in the presence of four images (from the film R) each of which reflects the adjacent one, horizontally and vertically. The notions of the development of a theme, of inversion, of mirror and retrograde inversion thus seem deployed, as if some of the figures of musical discourse were suddenly proposed visually. Moreover, the device of this installation makes the beams of the projectors cross two by two in order to constitute an image in the center of a given space. Two projectors, one above the other, face two others separated by a double-sided screen.