Lolcats
v i = { − V i if 0 ≤ t < T 2 , V i if T 2 ≤ t < T . {\displaystyle v_{i}={\begin{cases}-V_{i}&{\mbox{if }}0\leq t<{\frac {T}{2}},\\V_{i}&{\mbox{if }}{\frac {T}{2}}\leq t<T.\end{cases}}}
