PREFIX ex: <http://a.example>
PREFIX sx: <http://www.w3.org/ns/shex#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

[] a sx:Schema ;
    sx:shapes (_:vc1 <http://a.example/S1>) .

<http://a.example/S1> a sx:ShapeDecl ; sx:shapeExpr [ a sx:Shape ;
    sx:expression [ a sx:TripleConstraint ;
            sx:predicate <http://a.example/p1> ;
            sx:valueExpr _:vc1 ] ] .
_:vc1 a sx:ShapeDecl ; sx:shapeExpr [ a sx:NodeConstraint ;
    sx:minlength 5 ;
    sx:nodeKind sx:literal ] .