Joan Hinkemeyer, Special To The News Denver Rocky Mountain News 02-06-2004 PROSE, PLOTTING MAKE OLD THEMES NEW With her latest novel, The Rules of Engagement, Anita Brookner again explores the landscape of the isolated, enervated woman so prevalent in her earlier novels. This time around, she takes on the story of two London girls, both named Elizabeth, who start school on the same day in 1948. They agree that one, the narrator, shall remain "Elizabeth," while the other becomes "Betsy." Circumstances seem unequal for the girls. The orphaned Betsy is cared for by a dour maiden aunt, while Eli...