Two seniors (Walter Matthau and Ossie Davis) forge a prickly friendship in Central Park in an adaptation of Herb Gardner's stage play I'm Not Rappaport. Directed by the playwright himself, it's a slow-paced, sweetly depressing tale about the imposed obsolescence of the elderly and the different ways the two men handle it. (Davis' character doesn't make waves; Matthau is an unreconstructed, combative old Marxist who seeks to improve society, often by improving on the truth.) The author of A Thousand Clowns has made a career of chronicling ragtag urban eccentricity, and moviegoers weary of dialogue that sounds as though the screenwriters repeatedly slammed their foreheads against the keyboard will appreciate the wordsmithery, especially when uttered by two terrific veteran actors. But for all its warmth, humanism and bittersweet insights into human nature, there's something brittle and perhaps unintentionally exploitative about a story in which much of the climactic suspense involves the duo being cut up by drug dealers or petty criminals. It's disappointingly predictable, and it drowns out the subtler pleasures I'm Not Rappaport has to offer.