How to delete an literal UTF-8 object [by nodeID]?

Virtuoso Universal Server
1

Example:

ex:1 rdfs:comment "1" . 
ex:1 rdfs:comment "blah1" .
ex:1 rdfs:comment "blah1" .
ex:1 rdfs:comment "blah2" .
ex:1 rdfs:comment "blah2"@en .
ex:1 rdfs:comment "utf8_text_with_&_amps_etc"@ax .

The following code can delete the first triple :

qr := sprintf('sparql with ex: delete { ?s rdfs:comment ?s_comm . }
where {?s rdf:type ex:o1 .
filter (?s = <%s>)
filter (?s_comm = "%s")
}', s_id, s_comm);

However, I can’t delete other lines from the example.

Questions:

1
What’s the best way to delete an [really long utf8] literal object ?

2
I can get a IRI_id using (<LONG::bif:iri_id_num>(?s)) AS ?s_id for a node.
Is any similar function I can use to get id for a literal object and then delete it using this id ?

3
I can get “nodeID” for the whole triple and for the field using RDF/XML format:

fmt := 'RDF/XML';
qr := sprintf('sparql define output:format "%s" select distinct ?s ?s_comm { ?s ?p ?o . ?s rdf:type ex:o1 . ?s rdfs:comment ?s_comm} limit 1', fmt);

Will return:
&lt;rs:results rdf:nodeID=&quot;rset&quot;&gt;
  &lt;rs:result rdf:nodeID=&quot;sol193&quot;&gt;
   &lt;rs:binding rdf:nodeID=&quot;sol193-0&quot; .... /rs:binding&gt;
   &lt;rs:binding rdf:nodeID=&quot;sol193-1&quot; .... /rs:binding&gt;

Can I use nodeID “sol193” or “sol193-1” to delete the triple somehow ?

Best regards

2

update:
I can delete UTF-8 literals using serialize_to_UTF8_xml();
and a proper language description after “@”

s_comm := serialize_to_UTF8_xml(s_comm);
qr := sprintf('sparql with ex: delete { ?s rdfs:comment ?s_comm . }
where {?s rdf:type ex:o1 .
filter (?s = <%s>)
filter (?s_comm = "%s"@ex)
}', s_id, s_comm);

So, the issue is solved.

Anyway, It will be interesting to know if it’s possible to use an “field id” (e.g. “sol193” or “sol193-1” provided by output:format 'RDF/XML') to remove triples.