Domains of Paracompactness and Local Compactness
Brian Warrack · Canadian Journal of Mathematics · 1976
Given a class of topological spaces and a class of mappings of topological spaces, the -résolvant of is denned to be the class of topological spaces all of whose -images lie in . Whenever is closed under composition and includes identity maps, is easily seen to be the largest class of spaces smaller than which is closed under -images.