One of the Eilenberg-Steenrod axioms which states that, if is homotopic to , then their induced maps and are the same.
Homotopy Axiom
See also
Homotopic, Homotopy, Homotopy TheoryExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Homotopy Axiom." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HomotopyAxiom.html