I am reading an article about support vector machine (PDF) and one part of the document the author talks about the optimal margin classifier.
In the excerpt below, I do not understand why the author is switching from $\gamma$ to $ \hat{\gamma} $
I found in this question, What does a hat or star means in math? , that it can be used to denote a vector but the author already use the notation $\gamma^{(i)} $ when talking about a vector and earlier in the paper he says that
$$ \gamma = \min_{i=1, \dots , m} \gamma^{(i)} $$
so for me $\gamma$ is a vector too.
Bonus question: how should I read $ \hat{\gamma} $ ? "hat gamma" ?