Availability:built-in
attach_packs(+Directory)- search(+Where)
 - Determines the order in which pack library directories are searched. 
Default is to add new packages at the end (
last). Usingfirst, new packages are added at the start. - duplicate(+Action)
 - Determines what happens if a pack with the same name is already 
attached. Default is 
warning, which prints a warning and ignores the new pack. Other options arekeep, which is likewarningbut operates silently andreplace, which detaches the old pack and attaches the new. - replace(+Boolean)
 - If 
true, unregister all packs before registering the new packs. 
The predicate attach_packs/2 
can be used to attach packages that are bundled with an application. 
With the option replace(true),
attach_packs/2 
ensures that the application only relies on bundled packs.