Циклический однонаправленный список целых чисел

Program sp;
uses crt;
type
pInt = ^TElement; 
TElement = record  
          inf: integer;   
          next: pInt;  
          last: pInt;   
end;
var
ptrHead: pInt;    
ptrCurrent: pInt;    
i:integer;
 
 
procedure paste (i:integer; var ptrHead,ptrCurrent:pInt); 
  var 
ptrAddition:pInt;  
  begin
    new(ptrAddition);
  ptrAddition^. inf:=i;
  if ptrHead = nil
   then
    begin
    ptrAddition^.next := ptrAddition;
    ptrHead := ptrAddition
    end
else
begin   
 
  ptrAddition^.next := ptrCurrent^.next;
  ptrCurrent^.next := ptrAddition;
  end;
ptrCurrent:=ptrAddition;
  end;
 
 
procedure prosmotr (ptrHead:pInt);   
Var ptrAddition:pInt;
   begin
   while ptrAddition <> nil do
   ptrAddition:=ptrHead;
   repeat
 writeln(ptrAddition^.inf);   
   ptrAddition:=ptrAddition^.next;
  until ptrAddition=ptrHead;
   end;
 
 
function poisk (var ptrHead,ptrCurrent:pInt;i:integer):boolean;
  var
 ptrAddition:pInt;   
   begin
 if ptrHead <> nil then begin
    ptrAddition:=ptrHead;
   repeat
    ptrAddition:=ptrAddition^.next;
   until (ptrAddition=ptrHead) or (ptrAddition^.inf=i);
       if ptrAddition^.inf=i then begin
          poisk:=true;
      ptrCurrent:=ptrAddition;
        end
   else begin
     poisk:=false;
   end;
    end else begin
     poisk:=false;
      end;
       end;
 
 
   procedure delete (var ptrcurrent,ptrhead:pInt);
   var
   ptrAddition:pInt;
    begin
     if ptrCurrent <> nil then begin
   if ptrHead^.next<>ptrHead then begin
      ptrAddition:=ptrHead;
           while ptrAddition^.next <> ptrCurrent  do
ptrAddition := ptrAddition^.next;
ptrAddition^.next:=ptrCurrent^.next;
if ptrHead=ptrCurrent then
   ptrHead:=ptrCurrent^.next;
dispose(ptrCurrent);
ptrCurrent:=ptrAddition^.next;
end else begin
ptrHead:=nil;
dispose(ptrCurrent);
ptrCurrent:=nil;
end;
 end;
end;
BEGIN
   paste(1,ptrHead,ptrCurrent);
   paste (5,ptrHead,ptrCurrent);
   paste (3,ptrHead,ptrCurrent);
   paste (8,ptrHead,ptrCurrent);
   prosmotr(ptrHead);
   delete(ptrCurrent,ptrHead);
   writeln (poisk(ptrHead,ptrCurrent,3));
   prosmotr(ptrHead);
    end.