{
  "type":"Parallel","children":[
    {"type":"Ambient","id":"x","children":[
      {"type":"Parallel","children":[
        {"type":"Ambient","id":"call","children":[
          {"type":"Parallel","children":[
            {"type":"Serial","children":[
              {"type":"Out","id":"x", "children": [
                {"type":"In","id":"y", "children": [
                  {"type":"Open_","id":"*"}
                ]}
              ]}
            ]},
            {"type":"Ambient","id":"return","children":[
              {"type":"Serial","children":[
                {"type":"Open_","id":"*", "children": [
                  {"type":"In","id":"x"}
                ]}
              ]}
            ]}
          ]}
        ]},
        {"type":"Serial","children":[
          {"type":"Out_","id":"call", "children": [
            {"type":"In_","id":"y"}
          ]}
        ]}
      ]}
    ]},
    {"type":"Ambient","id":"y","children":[
      {"type":"Serial","children":[
        {"type":"In_","id":"call", "children": [
          {"type":"Open","id":"call", "children": [
            {"type":"Open","id":"return"}
          ]}
        ]}
      ]}
    ]}
  ]
}