The product formula

Abstract

A useful property of the Brouwer degree relates the degree of a composition of maps to the degree of each map. This property, which can be generalized for the Leray Schauder degree and in some cases for the A-proper maps is called the Product Formula. In G. Lopez, On the topological degree for A-compact mappings, J. Math. Anal. Appl. 159(2), 1991, 382-388 we develop a generalized degree theory for a class of mappings, this class contains the class of A-proper mappings and compact mappings, In this paper we prove a generalization of the Product Formula when one factor is of the Identity+Compact type and the other is an A-compact mapping.