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:predicate <http://a.example/p1> ;
            sx:valueExpr [ a sx:NodeConstraint ;
                    sx:values ( [ a sx:LanguageStemRange ;
                                sx:exclusion ("fr-be"
                                    "fr-cd"
                                    "fr-ch") ;
                                sx:stem "fr" ] ) ] ] ] .