Test math

${\begin{aligned}\ A\left(\sum _{i}a_{i}|v_{i}\rangle \right)=\sum _{i}a_{i}A\left(|v_{i}\rangle \right).\end{aligned}}$

(eqtn:linear_ defn)

For equations with named label:

$a={\frac {b}{c}}$

(eqtn:testeqn)