\foreach [count=\i] \cmd in {i>_, i_>, i<_, i_<}
\draw (3*\i,1) to[R, \cmd={\small\ttfamily\detokenize\expandafter{\cmd}}] ++(2.5,0);
\foreach [count=\i] \cmd in {i>^, i^>, i<^, i^<}
\draw (3*\i,0) to[R, \cmd={\small\ttfamily\detokenize\expandafter{\cmd}}] ++(2.5,0);