{
    "syllabus": {
        "depth": "core",
        "plural": "syllabi",
        "has": ["topic", "topics"],
        "in": false
    },
    "topic": {
        "depth": "mantle",
        "plural": "topics",
        "has": ["session", "sessions"],
        "in": ["syllabus", "syllabi"]
    },
    "session": {
        "depth": "crust",
        "plural": "sessions",
        "has": false,
        "in": ["topic", "topics"]
    },
    "book": {
        "depth": "core",
        "plural": "books",
        "has": ["part", "parts"],
        "in": false
    },
    "part": {
        "depth": "mantle",
        "plural": "parts",
        "has": ["chapter", "chapters"],
        "in": ["book", "books"]
    },
    "chapter": {
        "depth": "crust",
        "plural": "chapters",
        "has": false,
        "in": ["part", "parts"]
    }
}