anchor.diff:      log_details(Det, Halt),
       Context#context{active = ?SETS:new(), blocked = ?SETS:new()};
   
  -%% Is_process_alive message handler.
   handler(is_process_alive, Lid, #context{details = Det} = Context, TargetPid) ->
       TargetLid = lid:from_pid(TargetPid),
       log_details(Det, {is_process_alive, Lid, TargetLid}),
       Context;
   
  -%% Link message handler.
   handler(link, Lid, #context{details = Det} = Context, TargetPid) ->
       TargetLid = lid:from_pid(TargetPid),
       log_details(Det, {link, Lid, TargetLid}),
       Context;
   
  -%% Monitor message handler.
   handler(monitor, Lid, #context{details = Det} = Context, {Item, _Ref}) ->
       TargetLid = lid:from_pid(Item),
       log_details(Det, {monitor, Lid, TargetLid}),
       Context;
   
  -%% Process_flag message handler.
   handler(process_flag, Lid, #context{details = Det} = Context, {Flag, Value}) ->
       log_details(Det, {process_flag, Lid, Flag, Value}),
       Context;
  
positive.code:     NewActive = ?SETS:add_element(ChildLid, Active),
      Context#context{active = NewActive};
  
  %% Spawn_opt message handler.
  %% Similar to above depending on options.
  handler(spawn_opt, ParentLid,
  	#context{active = Active, details = Det} = Context, {Ret, Opt}) ->
  
negative.code: 	    Context#context{active = NewActive, error = Error}
      end;
  
  %% Return empty active and blocked queues to force run termination.
  handler(halt, Lid, #context{details = Det} = Context, Misc) ->
      Halt =
  