Math is an exact science. A mathematical proof is a demonstration of this exactness. Math can also be, according to those who study it, beautiful – an art form even; in that sense, Proof is an aptly titled film in which mathematics overlaps with metaphysics, poetry and even faith. Proof knows its characters’ field well enough to have a little fun with it (a character and his math department buddies have a band, and once of their songs is called “i”, as in ‘imaginary number;’ “They just stand there. They don't play anything for three minutes.”); on the other hand, it assumes at times, not entirely without reason, ignorance on the part of the audience. Now, I’ll confess that I didn’t know what a Germain prime was, but the characters do, so it’s a bit of awkward exposition when one explains it to another. Other than this, director John Madden truly lucked out with this movie – which is not to say he didn’t have anything at all to do with the success of the material –; in addition to being based on a Pulitzer Prize-winning play, you simply can’t go wrong when you only have four characters and three of them are played by Hopkins, Gyllenhaal, and Paltrow.