There are three types of settings for implied rules: First, Before Last, and Last. All your explicit rules: combination of both global and local rulebases are wrapped with those.
It looks like that:
----Implicit rules marked "First"
--All explicit rules: Global and Local, before the last one (can be global or local)
----Implicit rules marked "Before Last"
--Last explicit policy rule (local or global)
----Implicit rules maker "Last"
Mind, implied rules are defined on Domain level and not on Global one