Abstract The formulation of constrained system dynamics using coordinate projection onto a subspace locally tangent to the constraint manifold is revisited QR factorization Jacobian matrix extract suitable and integrating evolution along with that matrix, as solution evolves. A true continuation algorithm thus proposed track independent coordinates. It does not visibly affect quality but avoids...

a group g is said to be a (pf)c-group or to have polycyclic-by-finite conjugacy classes, if g/c_{g}(x^{g}) is a polycyclic-by-finite group for all xin g. this is a generalization of the familiar property of being an fc-group. de falco et al. (respectively, de giovanni and trombetti) studied groups whose proper subgroups of infinite rank have finite (respectively, polycyclic) conjugacy classes. ...