Since its name was reduced from The D. C. Black Repertory Company, The Rep. Inc. has become a far tighter, infinitely more professional group. In its smaller auditorium at 3710 Georgia Ave. NW, it is now presenting a group of related one-act plays as "Trilogy."

With considerable style, Jerry Huggins introduces the three plays, relating them to the "meaningful mixture of comedy and tragedy" within marriages. They are "Moonlight Arms," by Rudy Wallace; "De Ways of De Wimmens," edited by Jaye T. Stewart, who directed all three plays, and "The Owl Killer," by Phillips Hayes Dean.

Stewart's "De Ways of De Wimmens" is the most innovative and debt, a look through mime and Huggins' accompanying comments, at Adam and Eve, wittily performed by Arthur Daily Jr., and Mary Martin. Martin has an elfin personality and grace not unlike that of the noted broadway star.

This "annonymous folklore tale" has much in common with the breezy wit Roark Bradford presented in his collections of Biblical stories, "Ol' Man Adam an' His Chillun," which Marc Connelly adapted as "The Green Pastures."

Its spirited, clever performance suggests how black theater material has been evolving in recent years.Not long ago the idea of a contemporary production of "Green Pastures" would have been unthinkable.

With telling honesty, "Moonlight Arms" depicts a marriage rooted in deceptions, fated to fail but ultimately to be accepted by the scarred couple, played with assurance and passion by Lyn Dyson and Sadiqa Pettaway.

"The Owl Killer" is a perceptive, theatrically clever study by the author of "Paul Robeson" of how a father's acceptance of the Uncle Tom philosophy has affected his family. Juanita Norman, in the critical role of the mother, is affecting, with Robert Hatcher and Marsallay Brown-Rowe strongly supportive.

There are alternate casts for all three, and it is clear that Stewart has this illuminating, imaginative "Trilogy" under fine, theatrical control. Performances are Thursday through Sunday at 8 p.m.