prefix : <http://example.org/>

:alice a :Person;
       :knows :bob {| :since 2020 |} .

:bob a :Person ;
    :knows :alice . # No reification info for this triple, should trigger a validation error

:carol a :Person ;
      :knows :dave {| :since "not a number" |} . # Invalid datatype for :since, should trigger a validation error
