I would be grateful if someone takes a look at my solution to the following problem to see if it is correct. Thanks a lot for helping people even during the holidays.
Sorry, I have to delete the question due to some moral stuff.
I would be grateful if someone takes a look at my solution to the following problem to see if it is correct. Thanks a lot for helping people even during the holidays.
Sorry, I have to delete the question due to some moral stuff.
I assume that you want to get a comment on your proof.
Here it is: Your argument looks solid, but I don't understand, why you take $\pi_1(U)=\langle \alpha\rangle$ instead of $\pi_1(U)=\langle \beta\rangle$, because if you take away the point $x_0$ where $A,B,C$ are identified, an obvious deformation retraction in my opinion would retract $Z\setminus\{x_0\}$ to $D$. Then for $\phi\colon \pi_1(U\cap V)\to \pi_1(U)$ the image $\phi(\gamma)=\alpha^3$ is really evident by this deformation retraction.
All in all your solution is plausible.
Off topic: The knot $K$ should be a torus knot. :)