We consider a nonlinear equation , where the parameter is a perturbation parameter, is a differentiable mapping from to and , are Banach spaces. We obtain an abstract bifurcation theorem by using the generalized saddle-node bifurcation theorem.
Ping Liu. Yuwen Wang. "A Fold Bifurcation Theorem of Degenerate Solutions in a Perturbed Nonlinear Equation." Abstr. Appl. Anal. 2011 1 - 11, 2011. https://doi.org/10.1155/2011/302942