This paper treats the induced
function ℒ∗: [X,Y ] → [X,YP] when X and Y are spaces having “just enough”
structure and ℒ : Y → YP is a localization map. Special attention is paid to the
images of finite subsets of [X,Y ] and the preimages of finite subsets of [X,YP]. While
our results are not restricted to finite [X,Y ] we do, as an immediate corollary of our
main theorem, establish necessary and sufficient conditions for the finiteness of
[X,YP].