This function alters the security level on a point in the Cascade DataHub. If the current process security level is lower than the named point (symbol), then the function returns nil, otherwise it returns t. The initial security level for a process is 0.
Gamma> init_ipc("spt","spq");
t
Gamma> secure_point(#d,5);
nil
Gamma> set_security(9);
0
Gamma> secure_point(#d,5);
t
Gamma> secure_point(#d,12);
nil
Gamma> set_security(15);
9
Gamma> secure_point(#d,12);
t
Gamma>