"Derivative predicate" of W3C VC WG and "Expression Language" of OIDF ekyc-ida WG

Hi,

I am reaching out since there seems to be synergy with 'derived predicate' concept<https://www.w3.org/TR/vc-data-model/#dfn-predicates> of W3C VC spec and expression language<https://gruposantander.github.io/digital-trust-docs/assertions/claim-assertions-00.html#name-expression-language> concept being discussed in OpenID Foundation(OIDF)'s ekyc-ida (identity assurance) WG<https://openid.net/wg/ekyc-ida/>  in the context of selective disclosure.

This part<https://w3c.github.io/vc-imp-guide/#predicates> in the vc-imp-guide is the most detailed implementation of derived predicate that I have seen. Do you know if

  *   there is more specific proposal for how to express the derived predicates
  *   there is anyone actually implementing this feature

OIDF is discussing the concept of expression language<https://gruposantander.github.io/digital-trust-docs/assertions/claim-assertions-00.html#name-expression-language> which could be more generic than "ageOver18" property in VC imp-guide and ekyc-ida wg has been wondering if we could work together on this important topic.
OIDF's current proposal is outlined here<https://gruposantander.github.io/digital-trust-docs/assertions/claim-assertions-00.html>. For example for the alcohol purchase age, in the US it is ageOver18, but in Japan it is ageOver20. The concept of expression language would allow to express this as {"age" : { "gt" : "18", "lt" : "20" } } where gt is 'greater than' and 'lt' is less than.

Best,
Kristina
Identity Standards Team, Microsoft Corp.