Like the physicists in Copenhagen? Well, you'll love the mathematicians in The Five Hysterical Girls Theorem, the latest from Off-Off-Broadway's Target Margin Theater. The Rinne Groff play, directed by David Herskovitz, will play at the Connelly Theatre, April 19 May 13, with an April 26 opening.

Five concerns a gathering of "eccentric mathematicians" (are there any other kind?) at a seaside resort. There to argue theory, they instead fall headlong into a swamp of love, deception and rivalries.

Known for its highly stylized, director-driven productions of Shakespeare and lost American plays such as Preston Sturges' Strictly Dishonorable and Dorothy and DuBose Heyward's Mamba's Daughters, Target Margin is dedicating the 1999-2000 season to the production of new works.

Groff has acted in Target Margin shows before. A founder of Elevator Repair Service, her plays include Inky and House of Wonder. A cast of 18 will perform Five, including Peter Ackerman, Steven Rattazzi and Yuri Skujins.

Tickets are $15. The Connelly Theatre is located at 220 E. 4Th Street on the Lower East Side. For more information, call (212) 358-3657. --By Robert Simonson