Added a contents link block at the beginning and Section 12.14 on Cref.
Added a contents link block at the beginning and Section 12.14 on Cref.

AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog