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

:onetimeOK a :article ; :timetag 1 .
:onetimeNotOK a :article ; :timetag 10 .
:twotimesOK a :article ; :timetag 1, 2 .
:twotimesNotOK a :article ; :timetag 1, 10 .
:notimeOK a :article .