Cardinality of odrl:rightOperand

[simonstey]

https://w3c.github.io/poe/vocab/#term-isAnyOf:

Indicating that a given value is any of the right operand of the Constraint.

<http://example.com/policy:42>
  a odrl:Policy ;
  odrl:permission [
    a odrl:Permission ;
    odrl:target ex:asset_9898 ;
    odrl:action odrl:reproduce ;
    odrl:constraint [ 
        odrl:leftOperand odrl:media;
        odrl:operator odrl:isAnyOf ;
        odrl:rightOperand odrl:print, odrl:online ;
    ]
   ] .

but =>

http://w3c.github.io/poe/model/#constraint-class:

A Constraint MUST have either:

• one rightOperand property value of type literal, IRI [rfc3987], or RightOperand; or,
• one rightOperandReference property value (of type IRI [rfc3987]) for a reference to a right operand value.

[nitmws]

I get the need from this case using odrl:isAnyOf but that raises some questions:
What about

...
    odrl:constraint [ 
        odrl:leftOperand odrl:media;
        odrl:operator odrl:eq ;
        odrl:rightOperand odrl:print, odrl:online ;
    ]
...

• Are the "atomic" triples odrl:media odrl:isAnyOf odrl:print and odrl:media odrl:isAnyOf odrl:online ok?
• What is the logic of the atomic triples odrl:media odrl:eq odrl:print, odrl:media odrl:eq odrl:online: AND or OR or something else?

I guess these set-related operators isA, isPartOf, isAllOf, isAnyOf, isNoneOf need an explicit list/collection of values as rightOperand and a list is a single thing, does not require a changed cardinality.

[riannella]

@simonstey Perhaps we add this option as well:

A Constraint MUST have either:
one rightOperand property value of type literal, IRI [rfc3987], or RightOperand; or,
one rightOperand property value of type list of literals, list of IRIs [rfc3987], or list of RightOperands (for set-based operators); or,
one rightOperandReference property value (of type IRI [rfc3987]) for a reference to a right operand value.

Thoughts or other options?

@nitmws the odrl:eq examples would then be invalid

[vroddon]

Good point!

What about following the same strategy as with the andSequence? In such a case, an RDF list would follow.

[nitmws]

@riannella I was hoping the odrl:eq example is invalid - but one never knows ;-)

Re suggestion above: I would simply append the lists to the rightOperand definition:

one rightOperand property value of type literal, or? IRI [rfc3987], or RightOperand; or, list of literals, or? list of IRIs [rfc3987], or list of RightOperands (for set-based operators); or,
(Question: why are no "or"s before the IRIs?)

@vroddon this strategy already exists:

2.5.2 Logical Constraint Class - properties

A Logical Constraint must have one operand sub-property indicating the logical relationship of the compared existing constraints; its value is a list of the existing Constraint types.

@riannella there is an error: ... its value is a list of the existing Constraint instances.

... and operator andSequence:

all of the Constraints - in sequence - must be satisfied

[riannella]

Ok, done...and added note to vocab terms.

[nitmws]

Sorry to come back to this issue, but: if the rightOperand property may be a list of values I think this feature must be opened to the rightOperandReference property too:
one rightOperandReference property value of type
-- IRI [rfc3987]; or
-- list of IRIs [rfc3987]
for a reference to right operand value(s).

[riannella]

Done.
Also added notes to Vocab terms.