{
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  "input": {
    "type": "project",
    "input": {
      "type": "filter",
      "input": {
        "type": "bgp",
        "patterns": [
          {
            "type": "pattern",
            "termType": "Quad",
            "subject": {
              "termType": "Variable",
              "value": "x"
            },
            "predicate": {
              "termType": "Variable",
              "value": "p"
            },
            "object": {
              "termType": "Variable",
              "value": "o"
            },
            "graph": {
              "termType": "Variable",
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          }
        ]
      },
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        "args": [
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      {
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  "variables": [
    {
      "termType": "Variable",
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}
