4.1.10.3.12 IsUserIncluded

 procedure IsUserIncluded(
   userSid: SID
   groupOrAccountSid: SID)

The IsUserIncluded procedure returns true if userSid = groupOrAccountSid, or if the object identified by userSid is a member of the set returned by IDL_DRSGetMemberships (section 4.1.8) with the GroupMembersTransitive option applied to the object identified by groupOrAccountSid.