   When the result is an integer, it represents the time in milliseconds
   left until the timer will expire.
 
-  When the result is `false`, a timer corresponding to `timer_ref` could
-  not be found. This can be either because the timer expired, already has
+  When the result is `false`, a timer corresponding to `timer_ref` could not be
+  found. This can be either because the timer expired, because it has already
   been canceled, or because `timer_ref` never corresponded to a timer.
 
-  If the timer has expired, the timeout message has been sent, but it does
-  not tell you whether or not it has arrived at its destination yet.
+  Even if the timer had expired and the message was sent, this function does not
+  tell you if the timeout message has arrived at its destination yet.
 
   Inlined by the compiler.
   """

                         :min_bin_vheap_size | :priority | :save_calls |
                         :sensitive
  @doc """
  Sets certain flags for the process which calls this function.
  Returns the old value of the `flag`.

  See [`:erlang.process_flag/2`](http://www.erlang.org/doc/man/erlang.html#process_flag-2) for more info.
  """

  containing the PID and the monitoring reference, otherwise
  just the spawned process PID.

  More options are available; for the comprehensive list of available options
  check [`:erlang.spawn_opt/4`](http://www.erlang.org/doc/man/erlang.html#spawn_opt-4).

  Inlined by the compiler.
