A Generalization of Schur's Theorem
This paper is an excerpt from the author's 1968 PhD dissertation [Yale University, 1968] in which the (now) well-known result, commonly known as the Folkman-Rado-Sanders theorem, is proved. The proof uses (finite) alternating sums of integers and an 'iterated Ramsey theorem' in a way analogous to the proof of Schur's theorem using differences of integers and Ramsey's theorem for the coloring of the edges of a complete graph. The proof predates all others except J. Folkman, who based his proof on van der Waerden's theorem. The paper also contains the first published statement of the countable version of the theorem, which came to be misattributed to Graham and Rothschild, but predated their statement by three years.