Section 51: Problem 1 Solution
Working problems is a crucial part of learning mathematics. No one can learn topology merely by poring over the definitions, theorems, and examples that are worked out in the text. One must work part of it out for oneself. To provide that opportunity is the purpose of the exercises.
James R. Munkres
Show that if
are homotopic and
are homotopic, then
and
are homotopic.
There exist two homotopies
between
and
and
between
and
. Consider
such that
.