anchor.diff:                      end
           end;
       false ->
  -            debug("general postcondition fired for ~p:~p with response ~p", [Mod, Fun, Res]),
  +            postcondition_debug("general postcondition fired for ~p:~p with response ~p", [Mod, Fun, Res]),
               %% All other commands pass.
               false
       end.
  
positive.code:                         {error, _} ->
                              true;
                          _ ->
                              debug("node postcondition for ~p, operation succeeded, should have failed.", [Fun]),
                              false
                      end;
                  false ->
  
negative.code: %% determine whether the result `Res' (coming from the actual system)
  %% makes sense.
  postcondition(_State, {call, ?MODULE, induce_byzantine_message_corruption_fault, [_SourceNode, _DestinationNode, _Value]}, ok) ->
      postcondition_debug("postcondition induce_byzantine_message_corruption_fault: succeeded", []),
      %% Added message filter.
      true;
  postcondition(_State, {call, ?MODULE, resolve_byzantine_message_corruption_fault, [_SourceNode, _DestinationNode]}, ok) ->
      postcondition_debug("postcondition resolve_byzantine_message_corruption_fault: succeeded", []),
      %% Remove message filter.
      true;
  postcondition(_State, {call, ?MODULE, induce_async_partition, [_SourceNode, _DestinationNode]}, ok) ->
      postcondition_debug("postcondition induce_async_partition: succeeded", []),
      %% Added message filter.
      true;
  postcondition(_State, {call, ?MODULE, resolve_async_partition, [_SourceNode, _DestinationNode]}, ok) ->
      postcondition_debug("postcondition resolve_async_partition: succeeded", []),
      %% Removed message filter.
      true;
  postcondition(_State, {call, ?MODULE, induce_sync_partition, [_SourceNode, _DestinationNode]}, ok) ->
      postcondition_debug("postcondition induce_sync_partition: succeeded", []),
      %% Added message filter.
      true;
  postcondition(_State, {call, ?MODULE, resolve_sync_partition, [_SourceNode, _DestinationNode]}, ok) ->
      postcondition_debug("postcondition resolve_sync_partition: succeeded", []),
      %% Removed message filter.
      true;
  postcondition(_State, {call, ?MODULE, induce_cluster_partition, [_MajorityNodes, _MinorityNodes]}, ok) ->
      postcondition_debug("postcondition induce_cluster_partition: succeeded", []),
      %% Added message filter.
      true;
  postcondition(_State, {call, ?MODULE, resolve_cluster_partition, [_MajorityNodes, _MinorityNodes]}, ok) ->
      postcondition_debug("postcondition resolve_cluster_partition: succeeded", []),
      %% Removed message filter.
      true;
  postcondition(_State, {call, ?MODULE, join_cluster, [_Node, _JoinedNodes]}, ok) ->
      postcondition_debug("postcondition join_cluster: succeeded", []),
      %% Accept joins that succeed.
      true;
  postcondition(_State, {call, ?MODULE, leave_cluster, [_Node, _JoinedNodes]}, ok) ->
      postcondition_debug("postcondition leave_cluster: succeeded", []),
      %% Accept leaves that succeed.
      true;
  postcondition(#state{minority_nodes=MinorityNodes, partition_filters=PartitionFilters, node_state=NodeState}, {call, Mod, Fun, [Node|_]=_Args}=Call, Res) -> 
  