So I'm defining a struct but I also want to define a struct within it. This is the basic code I'm using. Several things I don't understand.

1. Why does the nested struct variable name needs to be the same as as struct name, in this case test2
2. Why do I need to put a semicolon at the end of the nested struct definition?

testStruct = struct test
(
    var1 = "a",
    test2 = struct test2
    (
        var3 = "c",
        var4 = "d"
    );,
    var2 = "b"
)