A class of Newton-type methods for computing singular points with corank gr
eater than or equal to 1 and index greater than or equal to 0 is presented.
The idea is to use a generalized Sherman-Morrison formula to define a regu
larizing perturbation of the Newton-increment formula. The quadratic conver
gence of the process is preserved. The proposed approach may be linked to t
ensor methods, bordered Jacobian techniques, and numerical Liapunov-Schmidt
reduction.