  The purpose of this paper is to expand the recent work of Sardar et al.
[Phys. Plasmas 23, 123706 (2016)] on the existence and stability of alternative
dust ion acoustic solitary wave solution of the combined modified Kadomtsev
Petviashvili - Kadomtsev Petviashvili (MKP-KP) equation in a nonthermal plasma.
Sardar et al. [Phys. Plasmas 23, 123706 (2016)] have derived a combined MKP-KP
equation to describe the nonlinear behaviour of the dust ion acoustic wave when
the coefficient of the nonlinear term of the KP equation tends to zero. Sardar
et al. [Phys. Plasmas 23, 123706 (2016)] have used this combined MKP-KP
equation to investigate the existence and stability of the alternative solitary
wave solution having a profile different from sech^2 or sech when L > 0, where
L is a function of the parameters of the present plasma system. In the present
paper, we have considered the same combined MKP-KP equation to study the
existence and stability of the double layer solution and it is shown that
double layer solution of this combined MKP-KP equation exists if L = 0.
Finally, the lowest order stability of the double layer solution of this
combined MKP-KP equation has been investigated with the help of multiple scale
perturbation expansion method of Allen and Rowlands [ J. Plasma Phys. 50, 413
(1993)]. It is found that the double layer solution of the combined MKP-KP
equation is stable at the lowest order of the wave number for long-wavelength
plane-wave perturbation.
