{
  "type": "project",
  "input": {
    "type": "filter",
    "input": {
      "type": "bgp",
      "patterns": [
        {
          "type": "pattern",
          "termType": "Quad",
          "subject": {
            "termType": "Variable",
            "value": "t"
          },
          "predicate": {
            "termType": "NamedNode",
            "value": "http://example.com/ns#source"
          },
          "object": {
            "termType": "NamedNode",
            "value": "http://example.com/ns#g"
          },
          "graph": {
            "termType": "DefaultGraph",
            "value": ""
          }
        }
      ]
    },
    "expression": {
      "type": "expression",
      "subType": "operator",
      "operator": "&&",
      "args": [
        {
          "type": "expression",
          "subType": "operator",
          "operator": "&&",
          "args": [
            {
              "type": "expression",
              "subType": "operator",
              "operator": "&&",
              "args": [
                {
                  "type": "expression",
                  "subType": "operator",
                  "operator": "istriple",
                  "args": [
                    {
                      "type": "expression",
                      "subType": "term",
                      "term": {
                        "termType": "Variable",
                        "value": "t"
                      }
                    }
                  ]
                },
                {
                  "type": "expression",
                  "subType": "operator",
                  "operator": "=",
                  "args": [
                    {
                      "type": "expression",
                      "subType": "operator",
                      "operator": "subject",
                      "args": [
                        {
                          "type": "expression",
                          "subType": "term",
                          "term": {
                            "termType": "Variable",
                            "value": "t"
                          }
                        }
                      ]
                    },
                    {
                      "type": "expression",
                      "subType": "term",
                      "term": {
                        "termType": "NamedNode",
                        "value": "http://example.com/ns#s"
                      }
                    }
                  ]
                }
              ]
            },
            {
              "type": "expression",
              "subType": "operator",
              "operator": "=",
              "args": [
                {
                  "type": "expression",
                  "subType": "operator",
                  "operator": "predicate",
                  "args": [
                    {
                      "type": "expression",
                      "subType": "term",
                      "term": {
                        "termType": "Variable",
                        "value": "t"
                      }
                    }
                  ]
                },
                {
                  "type": "expression",
                  "subType": "term",
                  "term": {
                    "termType": "NamedNode",
                    "value": "http://example.com/ns#p"
                  }
                }
              ]
            }
          ]
        },
        {
          "type": "expression",
          "subType": "operator",
          "operator": "=",
          "args": [
            {
              "type": "expression",
              "subType": "operator",
              "operator": "object",
              "args": [
                {
                  "type": "expression",
                  "subType": "term",
                  "term": {
                    "termType": "Variable",
                    "value": "t"
                  }
                }
              ]
            },
            {
              "type": "expression",
              "subType": "term",
              "term": {
                "termType": "NamedNode",
                "value": "http://example.com/ns#o"
              }
            }
          ]
        }
      ]
    }
  },
  "variables": [
    {
      "termType": "Variable",
      "value": "t"
    }
  ]
}