The public is invited to attend a single performance on Sunday, March 18, of the two-actor play "Dear Liar" in the Antilles School auditorium. The drama, based on four decades of letters exchanged between playwright George Bernard Shaw and a leading actress of his era, Beatrice "Stella" Tanner, will precede a series of theater workshops for students at the Frenchman's Bay school. Admission's free, but donations will be accepted; reservations are urged. Call Ms. Nelthropp at 776-1600.