PREFIX sx: <http://www.w3.org/ns/shex#>

[] a sx:Schema ;
  sx:shapes (<http://example.org/S>  <http://example.org/T>  <http://example.org/U>) .

<http://example.org/S> a sx:ShapeDecl ; sx:shapeExpr [ a sx:ShapeAnd ;
  sx:shapeExprs (
    <http://example.org/T>
    <http://example.org/U>
  ) ] .

<http://example.org/T> a sx:ShapeDecl ; sx:shapeExpr [ a sx:Shape ;
  sx:expression [
    a sx:EachOf ;
    sx:expressions (
      [ a sx:TripleConstraint ;
        sx:predicate <http://example.org/a> ;
        sx:valueExpr <http://example.org/S> ]
      [ a sx:TripleConstraint ;
        sx:predicate <http://example.org/c> ]
    )
  ] ] .

<http://example.org/U> a sx:ShapeDecl ; sx:shapeExpr [ a sx:Shape ;
  sx:expression [
    a sx:TripleConstraint ;
    sx:predicate <http://example.org/b> ] ] .