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 (<http://a.example/S1>) .

<http://a.example/S1> a sx:ShapeDecl ; sx:shapeExpr [ a sx:Shape ;
    sx:expression [ a sx:TripleConstraint ;
            sx:annotation ([ a sx:Annotation ;
                    sx:object "1" ;
                    sx:predicate <http://a.example/annot1> ]
                [ a sx:Annotation ;
                    sx:object "2" ;
                    sx:predicate <http://a.example/annot2> ]
                [ a sx:Annotation ;
                    sx:object "3" ;
                    sx:predicate <http://a.example/annot3> ]) ;
            sx:inverse true ;
            sx:predicate <http://a.example/p1> ] ] .