“…Lyapunov-Schmidt method can reduce equation (1) to equation (2), in which equation (2) has all the analytical and topological features of equation (1) (bifurcation diagram, multiplicity, etc. ), as such information can be found in [7], [8], [9], [13]. Singularities of smooth maps play an important part in the investigation of bifurcation solutions of BVPs.…”