DPTOK
flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
if (flags & DPTOK) {
flags &= ~(SIGNOK | DPTOK);
(flags & ~(EXPOK|DPTOK)) |
flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
(flags & ~(EXPOK|DPTOK)) |
(flags & DPTOK)) {
flags &= ~(SIGNOK | DPTOK);