SIG_UNBLOCK       211 src/prof.c         SIGPROCMASK(SIG_UNBLOCK, &set, NULL);
SIG_UNBLOCK       637 src/signal.c       if (how != SIG_SETMASK && how != SIG_BLOCK && how != SIG_UNBLOCK) {
SIG_UNBLOCK      2872 src/syslib.c     Scm_DefineConst(module, SCM_SYMBOL(SCM_OBJ(syslib_SIG_UNBLOCK__VAR)), SCM_OBJ(Scm_MakeInteger(SIG_UNBLOCK)));