PV_ANC
pv0->pv_flags &= ~(PV_NC|PV_ANC);
if ((pv0->pv_flags & (PV_NC|PV_ANC)) == PV_ANC) {
pv0->pv_flags &= ~PV_ANC;
if (pv0->pv_flags & PV_ANC) {
pv0->pv_flags |= PV_ANC;
pv0->pv_flags &= ~(PV_NC|PV_ANC);
if ((pv0->pv_flags & (PV_NC|PV_ANC)) == PV_ANC) {
pv0->pv_flags &= ~PV_ANC;
if ((pv0->pv_flags & PV_ANC) != 0) {
pv0->pv_flags |= PV_ANC;
flags = pv->pv_flags & ~(PV_NC|PV_ANC);
flags = pv->pv_flags & ~(PV_NC|PV_ANC);