Folds and Hopf bifurcations.

The continuation of folds for algebraic problems and the continuation of Hopf bifurcations requires two free problem parameters, i.e., NICP=2. For example, to continue a fold in Run 3 of demo ab, we have NICP=2, with PAR(1) and PAR(3) specified as free parameters. Note that one must set ISW=2 for computing such loci of special solutions. Also note that in the continuation of folds the principal continuation parameter must be the one with respect to which the fold was located.