\newcommand{\evec}[2]{\vec{#1}^{~#2}}

\newcommand{\lsl}{\ll}
\newcommand{\lsr}{\gg_\text{l}}
\newcommand{\asr}{\gg_\text{a}}

\newcommand{\clsl}{\ll_0}
\newcommand{\clsr}{\gg_{0, \text{l}}}
\newcommand{\casr}{\gg_{0, \text{a}}}