Such a control is not feasible if the threshold exceeds unity
(a global stability result for the smoking-present equilibrium
is provided for a special case). In 2011, Lahrouz et al. [5]
proved the global stability of the unique smoking-present
equilibrium state of the mathematical model developed by
Sharomi and Gumel. Also in 2011, Zaman [6] derived and
analyzed a smokingmodel taking into account the occasional
smokers compartment, and later [7] he extended themodel to
consider the possibility of quitters becoming smokers again.
In 2012, Ert¨urk et al. [8] introduced fractional derivatives into
the model and studied it numerically.