Hatcher-Algebraic-Topology · Problem 1.3.11

The Fundamental Group

Mathematics — Graph Theory · covering-spaces

Problem

Construct finite graphs

X_1

and

X_2

having a common finite-sheeted covering space

\tilde{X}_1 = \tilde{X}_2

, but such that there is no space having both

X_1

and

X_2

as covering spaces.