Secure the services of two excellent lead actors, find yourself a director who knows what he is doing, add the necessary complement of good supporting actors, and you can't go wrong with ''I'm Not Rappaport.''
The comedy, written by Herb Gardner (''A Thousand Clowns'') is currently being staged at the Olney Theater, where everything is just right, beginning with the principal performers.
The two men, who are on stage during the entire performance, are played by Richard Bauer and Michael W. Howell. Bauer, a veteran player at Washington's Arena Stage, plays Nat, the 81-year-old man who spends much of his free time sitting on a bench in Central Park.
He says, finally, in a burst of truth, that he was a waiter for the past 40 years, but you can hardly believe him. He is, at heart, a spinner of tall tales. The only thing we know about him for certain is that he was a socialist agitator in his youth.
Actually, he continues to agitate in his 80s, and the man who has to listen to most of this is an 81-year-old apartment house super. Midge (Howell) knows that Nat is a fraud, but he is frequently taken in by him.
James Waring, who directed the show, has not tampered with the timing, and that was wise. When the play first opened on Broadway in 1985, you could believe that a man as old as Nat would still be championing people like Lenin and Marx.
When first viewed, ''I'm Not Rappaport'' seemed sketchy and unfinished but was vastly entertaining. Today, we remember its time frame and accept it for what it is.
Nat's daughter is played by Barbara Andres, Alan Wade is the apartment dweller who must inform Midge that his services are no longer required, and Helen Hedman is Laurie, the girl who uses cocaine and can't always pay for it.
Chris Bauer, son of the star, is the punk who exacts protection money from the two old men, and Timmy Ray James is The Cowboy, the drug dealer who wants money from the girl.
All the secondary characters interact with the principals, and if most of this is left dangling, well, we know what to expect and we enjoy the play for what it is.
''I'm Not Rappaport'' wants, primarily, to be a comedy about two old men who entertain each other and us -- they do at the Olney, thanks to Bauer, Howell and the other members of the cast. And thanks to Waring, who also did the set, which looks like an exact replica of the one used on Broadway and at the Mechanic Theatre production.
''I'm Not Rappaport'' will continue at the Olney through Aug. 12.
''I'm Not Rappaport'' *** Two old friends amuse each other as they sit on a park bench Central Park.
CAST: Richard Bauer, Michael W. Howell, Alan Wade, Helen Hedman, Chris Bauer, Barbara Andrews, Timmy Ray James
DIRECTOR: James D. Waring
L RUNNING TIME: Two hours and 30 minutes with one intermission