《未知方程式》是一部由法国地区于1980年出品的剧情类理轮。该片由Francis Savel担任编剧，Francis Savel亲自指导拍摄。主要演员包括Gianfranco Longhi、Jean-Jacques Loupmon、Reinhard Montz等法国著名影星。
This long-lost masterpiece of * gay erotic cinema centers on a handsome young stud who rides his motorcycle through myriad *ual encounters, from a soccer game’s locker room to a phanta*agoric and deeply melancholy orgy. A labyrinth of all-male fantasies whose outstanding beauties always end up fading away while leaving their sensual protagonist dealing with his own loneliness, EQUATION was directed with supreme grace by the mysterious Dietrich de Velsa (aka Francis Savel/Frantz Salieri). A former painter, de Velsa was also the owner and artistic director of La Grande Eugène, one of the first drag cabarets in Paris. Years later, he collaborated with Joseph Losey on MR. KLEIN (1976) and DON GIOVANNI (1979). His one and only film, EQUATION TO AN UNKNOWN stands as one of the most extraordinary erotic films of all time.“The most melancholic * film I’ve ever seen. It’s very sad, and aesthetically beautiful. Just a young man wandering through several depictions of love and choreographies of love-making; it’s like a ceremony, a ceremony of fantasies, especially the last sequence where the main character recalls all his previous fantasies, which come one by one around his bed and make love to him. I think it’s one of the most beautiful film sequences of French cinema.” –Yann Gonzalez