{
  "type": "ShapeTest",
  "node": "http://a.example/n1",
  "shape": "http://a.example/S",
  "solution": { 
    "type":"TripleConstraintSolutions", "predicate":"http://a.example/p1",
    "valueExpr": { "type": "ShapeRef", "reference": "http://a.example/Sext" },
    "solutions":[
      { "type":"TestedTriple","subject":"http://a.example/n1","predicate":"http://a.example/p1","object":"http://a.example/n2",
        "referenced":
{
  "type": "ShapeTest",
  "node": "http://a.example/n2",
  "shape": "http://a.example/Sext",
  "solution": { 
    "type":"TripleConstraintSolutions", "predicate":"http://a.example/p2",
    "solutions":[
      { "type":"TestedTriple","subject":"http://a.example/n2","predicate":"http://a.example/p2","object":{ "value": "X" } }
    ]
  }
}
}]}}