We present convergence results of backward
differentiation formulas applied to several classes of stiff
initial value problems and discuss application of these methods to
nonlinear stiff problems.
An essential tool is the application of an appropriate
(nonlinear) transformation to the problem. The influence of the
corresponding time-dependent transformation to the numerical
method is studied. The approach here is based on the idea to write
multistep methods as one-step methods in higher dimensional space.
It uses further a non-diagonalizing decompostion of the companion
matrix [1], and a suitable variable norm. For details, see
[2].