Validating un-asserted claims

[afs]

Use case - make sure all claims about a person's age have a date and author.

A "claim" is not asserted in the data graph.

What is the best pattern to validate:

<< ex:Bob ex:age 23 >> 
    ex:date "2019-12-05"^^xsd:date ;
    ex:author ex:Claire
    .

ideally by targetting reifiers where the triple term has a certain property?

Expanded that syntax is:

  _:b rdf:reifies <<( ex:Bob ex:age 23 )>> ;
        ex:date "2019-12-05"^^xsd:date ;
        ex:author ex:Claire
    .

[ajnelson-nist]

I see disjunctive spelling of "if p then q" being the first step to crafting a shape.

"Then q" would be a couple property shapes min-counting ex:date and ex:author.

The part of "if p" pertaining to what's in the triple term, it looks like we haven't spelled out yet. Today's state of SHACL 1.2 Core just sees to have sh:TripleTerm discussion pertaining to sh:nodeKind and sh:NodeKindConstraintComponent. Can #517 (PR #574) be used to craft a selector?

Even after all that for a possible shape, this use case feels like it yearns for syntactic sugar for implication.

[HolgerKnublauch]

Suggestions:

sh:targetObjectsOf rdf:reifies?

or

sh:targetSubjectsOf ex:date

or

the reifier declares a type

<< ex:Bob ex:age 23 >> 
    a ex:Claim ;
    ex:date "2019-12-05"^^xsd:date ;
    ex:author ex:Claire
    .

ex:ClaimShape
    sh:targetClass ex:Claim .