Transcription: llStack.h contains the class template llStackT. In addition, llStack.h includes Stack.h because it defines StackT from which llStackT is derived. llStack.h also includes Iterator.h because it defines IteratorT from which llStackItterT is derived. The concrete class templates llStackT and llStackItterT defined in llStack.h. Stack.h is included because it defines class template StackT from which llStackT is derived. Iterator.h is included because llStack iterT is derived from the abstract base class IteratorT. AStack.h has a similar organization.