In page 70 of Hatcher's book, in the section Deck Transformations and Group Actions, the author defines a normal covering in the following way:
A covering space $p:\tilde X\to X$ is called normal if for each $x\in X$ and each pair of lifts $x_1,x_2$ of $x$ there is a deck transformation taking $x_1$ to $x_2$.
Afterwards, the author says this covering of $S^1 \vee S^1$
is a normal covering, I know why this is a covering, but I didn't understand why this is a normal covering based in this definition.
Please I really need help
Thanks a lot.