Making progress

I'd like to reiterate Pat's point.

If darkness is specified by the addition of something to the graph, then 
there is no way to avoid non-mon. We have been over this many times now. 
Could we please stop reopening this issue?

Jan, same problem occurs with your proposal too. Let us suppose a file 
contains:

<rdf:Descrpition rdf:about="eg:foo">
	  <eg:blah>wibble</eg:blah>
</rdf:Description>

Nothing is dark here. I then merge this with another file containing

<rdf:Descrpition rdf:about="eg:foo">
	  <eg:blah rdf:dark="yes">wibble</eg:blah>
</rdf:Description>

I have essentially retracted statements from the first file without touching it.

Darkness specification has to be *in the language*, not in a particular 
file using the language.

Jan