decrement
extern void decrement ANSI((Bigint*));
decrement(rvb);
decrement(Bigint *b)
itimerdecr(struct itimerspec *itp, const struct timespec *decrement)
timespecsub(&itp->it_value, decrement, &itp->it_value);
stat_backend->decrement(key, val.u.counter);
stat_backend->decrement("control.session", 1);
void (*decrement)(const char *, size_t);