Show that for binary distillation in a column with a single feed, a total condenser, and a partial reboiler,

\(\mathrm{FR}_{\text {MVC,dist }}=\frac{\mathrm{x}_{\mathrm{MVC}, \text { dist }}}{\mathrm{z}_{\mathrm{MVC}}}\left\lfloor\frac{\mathrm{z}_{\mathrm{MVC}}-\mathrm{x}_{\mathrm{MVC}, \text { bot }}}{\mathrm{x}_{\text {MVC,dist }}-\mathrm{x}_{\mathrm{MVC}, \text { bot }}}\rightfloor\)

If the LVC in the bottoms is very pure, what is the limiting value of \(\mathrm{FR}_{\mathrm{MVC}, \text { dist }}\) ?