[data-shapes] Define requirements for safe variables as part of the well-formedness conditions (#742)

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

== Define requirements for safe variables as part of the well-formedness conditions ==
Datalog requires that every variable in a rule head or negated body atom must appear in at least one positive body atom.
Currently, we only address safety for rule head variables, but it is not defined if it is required for negated body atoms.
We should add a definition for SHACL rules or an explanation how it relates to Datalog as part of the [well-formedness](https://raw.githack.com/w3c/data-shapes/gh-pages/shacl12-rules/index.html#wellformed).

Please view or discuss this issue at https://github.com/w3c/data-shapes/issues/742 using your GitHub account


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Received on Monday, 26 January 2026 11:13:50 UTC