# Hatcher 2.1.21

Hatcher, Algebraic Topology, Chapter 2, Section 1

21. Making the previous problem more concrete, construct explicit chain maps $s:C_n(X)\to C_{n+1}(SX)$ inducing isomorphisms $\widetilde{H}_n(X)\to\widetilde{H}_{n+1}(SX)$.
Proof.

$\square$