check user & library

Hello to all

can you tell me how can i check a user linked to a library or not (by natural programming) ?

i need a subprogram that get user&library and check user linked to library or not

thanks a lot

I found a subprogram that exactly cover my need:

NSC—L and other NSC–* in SYSSEC library.

by search “NSC—L” in natural security, you can find any things

Best Regards