<http://a.example/vc1> LITERAL minlength 4
<http://a.example/vc2> LITERAL maxlength 5
<http://a.example/vc3> LITERAL /^(ab)+$/

<http://a.example/S1> {
   <http://a.example/p1> @<http://a.example/vc1> AND @<http://a.example/vc2> AND @<http://a.example/vc3>
}