“…Liouville type theorems for equations (1.10) (i.e., nonexistence of nontrivial nonnegative solutions) in the whole space R n , the half space R n + and bounded domains Ω have been extensively studied (see [1,2,3,4,5,7,10,13,15,16,17,18,19,20,21,23,28,29,33,36,37,38,39] and the references therein). For other related properties on PDEs (1.10) and Liouville type theorems on systems of PDEs of type (1.10) with respect to various types of solutions (e.g., stable, radial, singular, nonnegative, sign-changing, • • • ), please refer to [1,3,6,12,14,16,18,22,27,28,29,32,35,39] and the references therein. These Liouville theorems, in conjunction with the blowing up and re-scaling arguments, are crucial in establishing a priori estimates and hence existence of positive solutions to non-variational boundary value problems for a class of elliptic equations on bounded domains or on Riemannian manifolds with boundaries (see [4,15,17,19,24,…”