@prefix bio: <http://purl.org/vocab/bio/0.1/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix time: <http://www.w3.org/2006/time#> .
@prefix ex: <http://example.org/ex#> .
@prefix thing: <http://example.org/thing#> .

# no blank node allowed
thing:maria a foaf:Person .

<a2s1g2.ttl>
  time:start "1867" ;
  time:end "1888" .

<a2s1g3.ttl>
  time:start "1888" ;
  time:end "9999" .