Hmm,
My head is spinning a bit now - I’m trying to understand something simple - 
"1"^^xsd:boolean.

So my reading says that is a valid lexical form (in the lexical space) for the 
value ’true’ (in the value space).
(http://www.w3.org/TR/rdf11-concepts/#dfn-lexical-space )
I think that ‘value space’ is where the other documents talk about 'RDF term’, 
but I’m not sure.

And I also I read:
"Literal term equality: Two literals are term-equal (the same RDF literal) if 
and only if the two lexical forms, the two datatype IRIs, and the two language 
tags (if any) compare equal, character by character.”
(http://www.w3.org/TR/rdf11-concepts/#section-Graph-Literal )

So the language processor will (must) take my lexical form
"1"^^xsd:boolean
and make it an RDF term
“true"

And then if I ask the store (sorry, I am rather engineering in this) if 2 terms 
are equal, it will always be comparing two similar terms (from the literal 
space), (probably, but see below):
“true"^^xsd:boolean

And I can expect a sensible querying engine to consider
"1"^^xsd:boolean
as a shorthand for
“true"

It could be confusing, which it was for a bit for me, because the equality 
constraint says "the two lexical forms”, but in this case there is more than 
one lexical from for the value form.
So I think it means that a processor must always choose the same lexical form 
for any given value form.
I am guessing that processors could consistently choose
"1"^^xsd:boolean
as the value form for
“true"
but that would be pretty perverse.

A little further confusion for me arises as to whether the datatype IRI is part 
of the value space.
I have taken off any ^^xsd:boolean from my rendering of the “true” in the value 
space because the documentation seems to leave it out.
(The table says: '<“true”, xsd:boolean>’ and ‘true’ are the literal and value.)
So I am left assuming that the datatype IRI is somewhere in the RDF term world, 
although we know it isn’t in the graph.
Not something I need to worry about as a consumer, as it is all an internal 
issue, I think, but I thought I would mention it.

Best
Hugh

-- 
Hugh Glaser
   20 Portchester Rise
   Eastleigh
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Mobile: +44 75 9533 4155, Home: +44 23 8061 5652



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