Namespace document cleanup

[afs]

• Corrects mistake: tehre was sparql:logical-and and also sparql:operator-and. Same for or.
• Add sparql:logical-not
• Operations like + are functions. Make both a sparql:Function and a sparql:Operator

I don't think sparql:Operator adds anything. It is used for operations (functions, and some functional forms) that have specific operator-style syntax. But they are functions and functional forms - syntax goes away.

Proposal: also remove sparql:Operator - this is the second commit of the PR.

[domel]

Two comments:

1. dc:date "2025-06-30" ; -> dc:date "2025-06-30^^xsd:date" ;
2. in sparql:isURI -> sparql:isURI owl:equivalentClass sparql:isIRI .

[Tpt]

Nit: it's a bit weird to have not-equals but greaterThan. I would normalize to camlCase or kebab-case

[afs]

Changing greaterThan et al. makes sense - the equivalent F&O functions are spelt - style.

Where SPARQL has a keyword, e.g hasLang, str*, I think hyphen in the local name isn't so good though hasLang* could be re-cased.

This PR already has approvals so I'll do a second PR.

[TallTed]

Should this sparql:Functional instead be sparql:Function?
and This form below be This function?

[afs]

"Functional Form" is the technical term.
It is used as a section heading in the document.

Functional Forms are not functions. They can look like them but they have different evaluation rules.

IF(condition, then, else) is not a function. It only evaluates one of the branches.

[kasei]

sparql:logical-not isn't listed in the spec as either a function or a functional form, though. It's listed only in the operator mapping section (along with functional forms such as logical-and, logical-or, and others).

[afs]

It is the use of fn:not within the operator dispatch table (EBV+the error handling).

It is a function, unlike &&.

Given && is logical-and and || is logical-or, expecting something for ! seems natural.