BST check

function TNode.CheckNodesOrder(var min, max: integer): Boolean;

var bufmin,bufmax: integer;

begin
  min := FInf;
  max := FInf;

  result:=True;

  if (FLeft<>nil)
  then
  begin
    Result:= FLeft.CheckNodesOrder(bufmin,bufmax) and (bufmax<FInf);
    if Result
    then min:=bufmin;
  end;


  if Result and (FRight<>nil)
    then
    begin
      Result:= FRight.CheckNodesOrder(bufmin,bufmax)and (bufmin>=FInf);
      if Result
      then  max:=bufmax;
    end;

end;