unit ulist;
interface

type
	P2list=^T2list;
	T2list=record
		key:integer;
		pprev,pnext:p2list;
	end;

function createElement2(key:integer):p2list;
procedure addfirstelement2(var PH:p2list; p:p2list);
procedure addlastelement2(var PH:p2list; p:p2list);
procedure InsertElementAfter2(pEl:p2list; p:p2list);
procedure InsertElementBefore2(pEl:p2list; p:p2list);
function deleteElement2(pEl:p2list):p2list;
function deletefirstElement2(var pH:p2list):p2list;
procedure disposeList2(var pH:p2list);
function countElements2(pH:p2list):integer;

type
 TlistAction2=procedure(key:integer);
procedure listAction2(ph:p2list; proc:TListAction2); 
  
implementation

function createElement2(key:integer):p2list;
begin
end;

procedure addfirstelement2(var PH:p2list; p:p2list);
begin
end;

procedure addlastelement2(var PH:p2list; p:p2list);
begin
end;

procedure InsertElementAfter2(pEl:p2list; p:p2list);
begin
end;

procedure InsertElementBefore2(pEl:p2list; p:p2list);
begin
end;

function deleteElement2(pEl:p2list):p2list;
begin
end;

function deletefirstElement2(var pH:p2list):p2list;
begin
end;

procedure disposeList2(var pH:p2list);
begin
end;

function countElements2(pH:p2list):integer;
begin
end;

procedure listAction2(ph:p2list; proc:TListAction2); 
begin
end;

end.