I won't call it "smart," because that would be redundant: Everything about Yasmina Reza's neo-classic is smart, and likewise this Ted Pappas-directed production. But there's one passage in the play that illuminates a lot about both Reza's craft and the themes of her cunning take on the vagaries of long-term male friendships.

The passage occurs late in this concise, intermissionless play, as the three characters finally drag the tensions between them into full light.

Till now, the conflict has been mostly between Serge, a dermatologist, and Marc, the engineer who thinks his buddy Serge is an idiot for paying a small fortune for a white-on-white abstract painting. But the long, climactic scene turns the focus on Yvan, the mediator and accommodator in this friendship triangle.

Yvan (played by Harry Bouvy) is the least professionally successful of the three, having just switched from one undesired job to another; he also has a private-life disaster waiting to happen, via a seemingly unadvisable marriage.

While Serge (Darren Eliker) and Marc (Rob Breckenridge) verbally -- and almost physically -- duke it out, Yvan lets drop an observation from his therapist (whom the intellectually overbearing Marc has, naturally, already announced is a fool).

I'm paraphrasing: "If I am who I am because I am who I am, and you are who you are because you are who you are, then I am who I am and you are who you are. But if I am who I am because you are who you are, and you are who you are because I am who I am, then I'm not who I am, and you're not who you are."

The neurotic Yvan's reading of his handwritten crib from his therapy session draws a nice laugh, and predictable derision from his two friends. But it's a measure of Reza's sophisticated structuring that this seeming bit of double-talk is actually one of the play's key points: Over 15 years, the friends have molded each others' lives so much that, when they are together, at least, they are no longer three individuals, but rather a unique sort of symbiotic organism -- one that requires its own kind of care to survive.

"Your friends need to be chaperoned, or else they'll get away," notes Marc at one juncture. It's a truism that, characteristically, cuts a couple ways, at least one of them ironic and at least one other poignant. And its an observation the Public's staging nicely follows up on in the closing scene, when the show's straightforward lighting scheme turns soft and shaded, suggesting relationships that might proceed with more thoughtfulness and less taken for granted.

Art continues at the Pittsburgh Public Theater (www.ppt.org) with eight more performances through Sun., June 27.