Symbols:L

The Set of All Linear Transformations
Their $\LaTeX$ codes are as follows:
 * $\mathcal L_R \left({G, H}\right)$ : \mathcal L_R \left({G, H}\right)
 * $\mathcal L \left({G, H}\right)$ : \mathcal L \left({G, H}\right)
 * $\mathcal L_R \left({G}\right)$ : \mathcal L_R \left({G}\right)
 * $\mathcal L \left({G}\right)$ : \mathcal L \left({G}\right)

Note
The usual notation for the set of linear transformations involves use of the mathscript font, that is: $\mathscr L$, whose $\LaTeX$ code is \mathscr L, but this does not render in many versions of $\LaTeX$.

Since this site migrated to MathJax, it has become possible to use the $\mathscr L$. However, this has not yet been attempted.