In the Aug. 30 obituary for Ruth Aaronson Bari, daughter Martha Bari was incorrectly identified as Dr. Bari. She is finishing her doctoral work at the University of Maryland. (Published 8/31/2005)

Dr. Ruth Aaronson Bari, 87, a professor emeritus of mathematics at George Washington University, died Aug. 25 at National Lutheran Home in Rockville of complications from Alzheimer's disease. She had lived in Silver Spring since 1963.

A native of Brooklyn, N.Y., she fell in love with the beauty and purity of math at Brooklyn College, where she received a bachelor's degree in 1939.

She enrolled in the doctoral program in math at Johns Hopkins University, but the end of World War II thwarted her plans. Her daughter recalled that she acceded to a suggestion by the university that women in the graduate program give up their fellowships so that men returning from the armed forces could continue their studies. She received her master's degree from Johns Hopkins in 1943.

For the next two decades, she raised three daughters and then decided -- at her husband's insistence -- to fulfill her long-delayed doctorate dream. She reapplied to Johns Hopkins and was accepted provisionally; she had to redo master's-level course work so the university could be assured that she was still capable of doing doctoral-level math.

Working late into the night, she completed her dissertation on "absolute reducibility of maps of at most 19 regions." She received her PhD in 1966 at age 47.

"Her thesis, I'm told, was extraordinary," a daughter, New York Times science reporter Gina Kolata, wrote in a 1987 article about her mother. "Shortly after she got her degree, William Tutte, a renowned mathematician in her field, invited her to spend two weeks in his department at the University of Waterloo in Canada, lecturing on her work. He paid all of her expenses and gave her $500 a week, which, my father reminds me, was quite a lot of money in those days."

She joined the GWU faculty in 1966 and was promoted to full professor a few years later. An expert on graph theory, she wrote a pioneering paper in the area of graphs and the algebraic structures known as homomorphisms.

Concerned in the early 1970s that math teachers in the District's public schools were not as well prepared in the field as they needed to be, she used a grant from the National Science Foundation to start a master's-degree program in teaching mathematics. She also took part in a class-action lawsuit against GWU, protesting pay and promotion inequities affecting female faculty members.

Another daughter, Dr. Martha Bari, an art historian at Hood College, recalled that the perennial math problem her mother had addressed in her dissertation -- involving four-color conjecture -- was finally solved in 1976 by two professors relying on massive computer number-crunching. "Don't you feel cheated after all that work you did?" Bari asked her mother.

Dr. Bari assured her daughter that she did not. "I'm just grateful that it was solved within my lifetime and that I had the privilege to witness it," she said.

Dr. Bari retired in 1988.

A daughter, Judi Bari, a prominent environmental activist with EarthFirst!, died in 1997.

In addition to her two daughters, Kolata of Princeton, N.J., and Bari of Silver Spring, survivors include her husband of 64 years, Arthur Bari of Rockville; and four grandchildren.

Dr. Ruth Aaronson Bari, shown with her husband, Arthur, wrote a pioneering paper in the area of graphs.