Show that in the presence of personal income tax and corporate income tax, the gain from leverage to stockholders is given by the expression

\[G_{l .}=\left[1-\frac{\left(1-\tau_{c}\right)\left(1-\tau_{s}\right)}{1-\tau_{b}}\right] B\]

where \(B\) denotes the market value of the debt in the leveraged firm.