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W3C's Notation 3 (N3) Community Group
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odd sequence in N3 semantics #198

Open pfps opened 1 year ago

pfps commented 1 year ago

https://w3c.github.io/N3/reports/20230703/semantics.html says that QI is a mapping from ground graph terms to ground graph terms. The conditions on QI appear to require that QI is total. But later on "QI is allowed to be the empty mapping. " This appears to contradict the earlier requirements on QI. As well, there does not appear to be a requirement that the range of QI be a subset of the domain of discourse so the rest of the sentence is also suspect.

doerthe commented 1 year ago

For your second point: The range of QI does not necessarily need to be a subset of the domain, but if QI(gt) is not in the domain for some graph term gt, then none of the triples using gt can be true. This difference is also interesting if you think about quantification: you always quantify over the domain of discourse, but not all representations of graph terms you could ever construct are necessarily in that domain.

This brings me to your first comment: you are right, the function QI needs to be total and QI should therefore not be the empty mapping, that is a mistake.

Thank you for your comment, I will fix the text as soon as possible.