You have declared a variable in a procedure, but you never actually use it. -H

program Produce;
(*$HINTS ON*)

  procedure Local;
    var i : Integer;
  begin
  end;

begin
end.
    program Solve;

(*$HINTS ON*)

  procedure Local;
  begin
  end;

begin
end.

One simple solution is to remove any unused variable from your procedures. However, unused variables can also indicate an error in the implementation of your algorithm.