Allegheny County (PA) Airport (KAGC) is located in Class D airspace.

The KAGC Class D is located inside the boundaries of the Pittsburgh (PA)
International (KPIT) Class B airspace, except for one small portion of the
Class D which extends outside of the Class B.

If flying into or out of KAGC, staying below the ceiling of the Class D,
and making entry to or exit from the Class D in that small portion that
extends ouside of the Class B, are you governed by the Class B regs or the
Class D regs?

Thank you!