$$\pi_(a|s) = \left{ \begin{array}{ll} \displaystyle 1 & \textrm{if}\ a=\arg\max_{a\in A}q_(s,a)\ \displaystyle 0 & \textrm{otherwise} \end{array} \right.$$
$$\pi_(a|s) = \left{ \begin{array}{ll} \displaystyle 1 & \textrm{if}\ a=\arg\max_{a\in A}q_(s,a)\ \displaystyle 0 & \textrm{otherwise} \end{array} \right. $$
$$ \pi_(a|s) = \left{ \begin{array}{ll} \displaystyle 1 & \textrm{if}\ a=\arg\max_{a\in A}q_(s,a)\ \displaystyle 0 & \textrm{otherwise} \end{array} \right. $$
$$\pi_(a|s) = \left{ \begin{array}{ll} \displaystyle 1 & \textrm{if}\ a=\arg\max_{a\in A}q_(s,a)\ \displaystyle 0 & \textrm{otherwise} \end{array}\right.$$
inline: $\pi_(a|s) = \left{ \begin{array}{ll} \displaystyle 1 & \textrm{if}\ a=\arg\max_{a\in A}q_(s,a)\ \displaystyle 0 & \textrm{otherwise} \end{array}\right.$