[data-shapes] [Rules] Stratification (#687)

afs has just created a new issue for https://github.com/w3c/data-shapes:

== [Rules] Stratification ==
Stratification is used to gives conditions on the order rules are evaluated so that the output is predicable. Negation depends on order of execution.
https://en.wikipedia.org/wiki/Datalog#Negation

The [spec](https://w3c.github.io/data-shapes/shacl12-rules) should define [stratification](https://w3c.github.io/data-shapes/shacl12-rules/#stratification
 and provide an algorithm to calculate the layer numbering.

This can be done for [rule](https://w3c.github.io/data-shapes/shacl12-rules/#dfn-rule) but if applied to [rule elements](https://w3c.github.io/data-shapes/shacl12-rules/#dfn-rule-body-element) we may be able to define evaluation for slighter more generally.

For example. `NOT` can defined to require conditions dependencies on triple patterns with variables that are used in the `NOT` pattern, and not for unrelated variables.

Recursion of unrelated triple patterns could then be allowed. This is equivalent to rewrite, replacing the rule with several rules. On the other hand, it might not be a good idea to over-complicate the conditions for something that can be written, albeit in a different form.



Please view or discuss this issue at https://github.com/w3c/data-shapes/issues/687 using your GitHub account


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Received on Wednesday, 3 December 2025 13:25:53 UTC