One of the many good things about the movie version of David Auburn's Pulitzer Prize-winning play, "Proof," is the fact that it conveys absolutely no sense of its theatrical origins. It's so fluid and cinematic that it's hard to even envision how the piece worked on stage.

Considering how difficult this is to bring off -- and considering how many great American plays of the past ("Death of a Salesman," "Our Town," etc.) have resisted translation to the language of film -- the feat is worth a moment of special praise.

At the same time, the full dramatic intensity and weight of the work also comes through undiminished and uncompromised. Like the best play-to-movie adaptations, it leaves us feeling that we've had a powerful and enriching theatrical experience.

It's the story of Catherine (Gwyneth Paltrow), the 27-year-old daughter of a Chicago mathematician (Anthony Hopkins) who revolutionized the field in his early 20s but began to "go crazy" soon thereafter and ended his days scribbling notebooks full of incoherent nothings.

Like her father, who she nursed through the five years before his death, Catherine has both a flair for higher math and a tendency toward emotional imbalance, and her fear -- shared by her manipulative older sister (Hope Davis) -- is that she will end up the same way.