I have to learn for a very important test on monday but I don't get along with the following exercise from Bredon's book »Topology and Geometry«:
Let the projective plane $P^2=U_1\cup … \cup U_n$ where each $U_i$ is homeomorphic to the plane. Put $V_i=U_1\cup … \cup U_i$ for $1\leq i
Any hints or proofs?
Thank you very very much!