DEFINITION MODULE SimpleStks;

EXPORT QUALIFIED Stack, PushOnto,RemoveTopItemFrom,
		 TopValueOf, PopFrom, initialise, empty;

TYPE Stack;

PROCEDURE PushOnto (VAR stack : Stack; value : CARDINAL);
PROCEDURE RemoveTopItemFrom (VAR stack : Stack);
PROCEDURE TopValueOf (stack : Stack) : CARDINAL;
PROCEDURE PopFrom (VAR stack : Stack) : CARDINAL;
PROCEDURE empty (stack : Stack) : BOOLEAN;
PROCEDURE initialise (VAR stack : Stack);
END SimpleStks.
