anchor.diff:               unlink(P1),
                unlink(P2),
                catch exit(P1, kill),
  -             catch exit(P2, kill)
  +             catch exit(P2, kill),
  +             wait_until_dead(P1),
  +             wait_until_dead(P2)
        end,
        [
         fun(_) ->
  
positive.code:                      ]}
      ].
  
  -endif.
  
negative.code:     unlink(P1),
      unlink(P2),
      catch exit(P1, kill),
      catch exit(P2, kill),
      wait_until_dead(P1),
      wait_until_dead(P2).
  
  async_fold_config() ->
      [
  