${\mathit{I}\mathit{B}}_{\mathit{S}\mathit{N}}=\frac{\left\{{\mathit{P}\mathit{o}\mathit{p}}_{\mathit{c}\mathit{o}\mathit{u}\mathit{n}\mathit{t}}\mathit{*}\left[\frac{{\mathit{G}\mathit{B}}_{\mathit{C}\mathit{C}\mathit{H}\mathit{S}\mathit{ }\mathit{p}\mathit{r}\mathit{o}\mathit{p}}}{{\mathit{D}\mathit{i}\mathit{s}\mathit{c}\mathit{l}\mathit{o}\mathit{s}\mathit{u}\mathit{r}\mathit{e}}_{\mathit{S}\mathit{N}\mathit{ }\mathit{p}\mathit{r}\mathit{o}\mathit{p}}}\right]\right\}}{{\mathit{G}\mathit{B}}_{\mathit{S}\mathit{N}\mathit{ }\mathit{p}\mathit{r}\mathit{o}\mathit{p}}}$