In Top, how do conjugate homorphisms of groups induce homotopies of classifying spaces? They exist-exist— there's an abstract proof, but how is BG -->→ BH written in terms of the homotopy??
If G and H are only H-spaces, a homomorphism induces a map of a projective plane. In Top, how do cojugateconjugate H-maps induce homotopies of maps of projective planes??