/*  -*- prolog -*-
 ******************************************************************************
  File: stack.pro
  Description: The stack ADT. From Luger & Stubblefield. A
   single predicate, stack(), can be used to define the push,
   pop, and peek predicates, by varying the arguments to stack().

   For example, where Stack is a list of the form [H|T], here is how
   you would define push(), pop(), and peek() in terms of stack().

     push(X, Stack, NewStack) :- stack(X, Stack, NewStack), NewStack=[X|Stack].
     pop(X, NewStack,Stack) :-  stack(X, NewStack, Stack), Stack = [X|NewStack].
     peek(X, Stack, Stack) :-  stack(X, _, [X|Tail]), Stack = [X|Tail].

****************************************************************************** */

empty_stack([]).

stack(Top, Stack, [Top|Stack]).   /* used for push, pop and peek */

member_stack(Element, Stack) :- 
	member(Element,Stack).

add_list_to_stack(List,Stack,Result) :- 
	append(List,Stack,Result).

reverse_print_stack(S) :- empty_stack(S).
reverse_print_stack(S) :- 
	stack(E,Rest,S),
	reverse_print_stack(Rest),
	write(E),nl.

member(H,[H|T]).
member(X,[_|T]) :-
	member(X,T).