Henri Cartan, one of the world's foremost mathematicians of the last half of the 20th century, died Aug. 13 in Paris at age 104.

He was acclaimed for his research in pure mathematics, including algebra, topology and the analytic functions of complex variables. He also was an influential writer and teacher. In the United States, he worked with mathematician Samuel Eilenberg. Their 1956 book, "Homological Algebra," was regarded as a classic of mathematics and a reference for many researchers.

WASHINGTON POST