[
    $empty: [
        [ ]
        [:]  -- colon means empty catalog
    ]
    $list: [
        [
            1
            2
            3  -- last
        ]
        [
            $alpha
            $beta
            $delta
            $gamma
        ]($type: /nebula/collections/Set/v1($ItemType: /nebula/strings/Symbol/v1))
        [
            target
            any
            "foo[Bb]ar"?
            none
            #L7JJGPAYAH7T55J5Q9Q75RRL0SVW8F1X76HWW90CHJJQAH6270DH
            $symbol
            $reserved-5
            ~P3Y2M1D
            <2017-07-04>
            <https://google.com/>
            v1.2.3
            "
                "
                    nested
                    multiline
                    text
                "
            "
            '0110101101010001'($encoding: $base02)
            .5
            75%
            undefined
            ∞
            -π
            ~π
            τ
            φ
            (3, 4i)
            [
                "one"
                "two"
                "three"
            ]
            [
                $foo: $bar
                $bar: 25($range: [1..100])
                $baz: none  -- no value
            ]
        ]
    ]
    $catalog: [
        $a-1: "a"
        $b-2: "b"
        $c-3: "c"
        "1.": true
        "iffy": .5
        ".0": size + 1
        true: false
        .5: true
        50%: 20%
        ∞: undefined
        "^.*$"?: none($strict: true)
        #665VRFNFZMQX09TSKHJSD1HL567F4FF7: #CT41AC8K5AZBMJF88W60F40SZQCMA0XN($size: 20)
        $foo: $bar($baz: $baz)
        /name: /name($relative: false)
        ~P0D: ~P1Y3M24DT7H32M15S
        <2017-04-01>: <2017-04-01>($country: "USA")
        <https://craterdog.com/>: <https://bali-nebula.net/nebula/examples>(
            $foo: 5
            $bar: false
        )
        v1: v2.3($patch: true)
        "key": "value"($mediaType: "text")
        'MMNBXR9TC237PK269GLFZ4J4XA4R9LF1': '0111010110101100100011'($encoding: $base16)
        ~π: ~π($units: $radians)
        τ: -6.28318531
        (1, 2i): (5 e^~1.4i)
        $sequence: [
            "short"
            "sequence"
        ]($type: /nebula/collections/Queue/v1)
        $table: [
            $a: e
            $b: -π
            $c: φ
            $d: τ
            $e: ∞
        ]($type: /acme/examples/Foo/v1.2.3)  -- example type
        $procedure: {
            if condition then {
                return true
            } else {
                throw exception
            }
        }($condition: /nebula/elements/Boolean/v1)
    ]
    $procedures: [
        {
        }
        {
            $foo := bar
            $bar := baz
        }($bar: $baz)
        {
            if condition then {
                $x := y
            } else {
                return x
            }
        }(
            $y: 5
            $baz: none
            $condition: true
        )
    ]
    $binaries: [
        ''($encoding: $base02)
        '
            001011011001110101000001010011111011110100110111000111100000
            00000100011001001101
        '($encoding: $base16)
        '
            C3393B1543ACD32429A15D22A557C42DDD227DDDDA69D9CD55A7923D214A
            49D8A9C1AAC975C02B58
        '
        '
            51540EF86BC3660D4F4F95D3EF1E57E5A79396A2C6D4590A50202A849881
            45ADAEB3DC84737D6021CC0DB3E13EFDC90DBF4917172BA27E426FA6398A
            790CE723DB70712361EDDF7DAEE5EDB706CA1A631DBCD80988E98171E166
            C8BF8D3BE0E97F6E655105E74D96F9F86026504B752854B9316D0AB8263A
        '($encoding: $base16)
        '
            234VDR3AFBR3N596XPHCZL7HNL2NX9FTV858QH33QQR62GP176PW7DAKCB1H
            DW411WRC0YS71NWKA93S
        '($encoding: $base64)
    ]
    $texts: [
        "simple"
        "This is a sentence."
        "This contains a \"quoted\" word."
        "This contains a \n new line character."
        "This contains a {procedure}."
    ]
    $moments: [
        <1000>($country: "Atlantis")
        <1962-04-01>($city: "New York City")
        <1962-04-01T06:31>($city: "San Francisco")
        <1962-04-01T06:31:59.726>(
            $city: "Denver"
            $region: "Colorado"
            $country: "USA"
        )
    ]
    $ranges: [
        [-3..5]
        [π<..τ]
        [0..<]
        [0..<∞]
        [..<-1]
        [-∞..<-1]
        [<..<]
        [-∞<..<∞]
        [..]
        [-∞..∞]
    ]
]