Reprinted from yesterday's late editions.

"Philadelphia, Here I Come!," Brian Friels's beautiful play about a youth's leave-taking of his native island, is being given a splendid production at the Olney Theater, where it opened Tuesday night. Our country stage has had a summer of quality plays, and this one ranks with the best of them. Plan to see it before the run ends Sept. 11.

"Philadelphia" is a good illustration of how far off the mainstream our playwrights have been getting since its American arrival in 1966. The play has a richness of texture, character delineation for 14 vivid roles, an expert assurance of construction and disciplined craftsmanship presently being ignored by our overpraised "news" writers.

Friel's central figure is Gareth O'Donnell, and he supplies two of him, the "public" Gar, whom we and everyone else see, and the "private" Gar, expressing the character's inner thoughts.

Director James D. Waring has located a tip-top cast especially for those tandem roles of Gar. Tom-Patrick Dineen, as Gar "public" withholds Gar's thoughts with his nerve ends showing Jariath Conroy, as Gar "private" creates from private thoughts a mocking aware intelligence of biting acuity. They are well-paired, and Lillian Mckiver's identical costuming allows, too, some quiet humor.

Friel's intent is to suggest the effect the American Dream has had on a lonely, distant fellow feeling his way through 25 years of adolescence in a small Irish village. After the death of his young mother, Gar has been brought up by the father who was 21 years his wife's elder. Theold man is non-communicative, and the youth's efforts to pull up a boyhood memory are dramatized through the outward and inward personalities Friel depicts.

From American films and magazines, Gar has grand illusions of the United States and from his dead mother's sister, who went to Philadelphia and now invites her nephew to join her there, he catches a warning of material vulgarity but a spirited releif from boredom. In a sturdily constructed scene,Helena Carroll brings this character to glorious life, richly funny, essentially pitiable.

Other experts in Waring's company include Roger DeKoven, excellent as Gar's repressed father, and Pauline Flanagan, as the housekeeper with troubles of her own, a subtly detailed portrait of assured distinction; George Vogel, as Carroll's husband. Judith McGilligan as the girl Gar loses, and Frank Hamilton, as a checkers-playing canon.

Rolf Beyer's evocative set and a slash of music by the Celtic Folk are other details in this quality production of a quality play.