anchor.diff:      projection_transition_is_sane(P1, P2, RelativeToServer, false).
   
   projection_transition_is_sane(P1, P2, RelativeToServer, RetrospectiveP) ->
  +    put(why2, []),
       case projection_transition_is_sane_with_si_epoch(
              P1, P2, RelativeToServer, RetrospectiveP) of
           true ->
  
positive.code:             %% P_latest is not sane.
              %% By process of elimination, P_newprop is best,
              %% so let's write it.
              ?REACT({c100, ?LINE, [not_sane]}),
              react_to_env_C300(P_newprop, P_latest, S)
      end.
  
  
negative.code:                     case catch(lists:last(UPI1)) of
                          UPI1_tail when UPI1_tail == Author2 ->
                              ?RETURN2(true);
                          UPI1_tail ->
                              ?RETURN2({expected_author2,UPI1_tail})
                      end
              end
      end.
  