Published online by Cambridge University Press: 24 October 2008
Introduction. Let h*(X, A) be an extraordinary cohomology theory defined on the category of finite CW-pairs, that is, a cohomology theory satisfying all the axioms of Eilenberg and Steenrod (7) except the dimension axiom. This paper has three objects: to define and investigate the properties of the associated mod p cohomology theory h*(X, A; Zp) (see also (9)), to show that (with certain restrictions) if h*(X, A) is a multiplicative cohomology theory, so is h*(X, A. Zp), and lastly to generalize the notion of Bockstein coboundary homomorphisms and the apparatus of the Bockstein spectral sequence (see (4)) to an extraordinary cohomology theory.