Proof began its life as a Pulitzer prize-winning play by David Auburn that wowed them on Broadway for many years, the next-longest running production after Peter Schaffer's hit Amadeus. Now it has been adapted into a movie starring Gwyneth Paltrow (Shakespeare In Love) and Sir Anthony Hopkins (Silence Of The Lambs). It explores mathematics, madness and affairs of the heart. Paltrow plays Catherine, a dutiful daughter in mourning for her recently departed dad, Robert (Hopkins), a brilliant mathematician who descended into mental illness and ill health. After his death ' and after a few visions of her deceased dad - Catherine fears that she too is losing her mind, especially when her ruthlessly pragmatic sister Claire (Hope Davis) turns up to take care of business and his estate. Along with grieving and grappling with her sanity a mystery is unfolding at the same time, as discovered by one of Robert's former students, Hal (Jake Gyllenhaal), also Catherine's new lover: did Catherine or her father write the revolutionary maths formula found locked away in a drawer upstairs? Like the hardest of maths questions, the answer is complicated' Some ridicule Gwyneth Paltrow's talent for screen melancholy; I've enjoyed it for many years in films like Possession (2002), The Royal Tennebaums (2001), The Talented Mr. Ripley (1999) and Se7en (1995). Without it there is no way she would have been able to make this 'is-she-or-isn't-she-crazy' role work as well as she does. Hers is a very demanding character wrapped up in a thematically demanding film about trust, love, genius and finding one's true identity. What doesn't work so well is this film adaptation. Granted 'maths' isn't a very sexy subject for cinema (few films have managed to do it successfully as Darren Aaronofsky's low budget 1998 feature Pi), and neither is mental illness 'two topics already visited in Ron Howards 2001 crowd-pleaser A Beautiful Mind. While Proof is nowhere near as sentimental or stereotyped as that movie, it is still too ham-fisted in the delivery of its high-reaching message about love and the fine line between genius and insanity. Proof is well-performed and flirts with being interesting. It is a technically precise exercise but I'm not sure it adds up to very much by the time the end credits roll.