Array() can contain Array(). I do it lots. But there's the issue of debugging things and of knowing what's in an array full of embedded arrays.
So I wrote PArray().
Tcl has a function of the same name which does the same thing. And the output looks very like an Euphoria sequence (now there's a nice language) but you can change that if you want to.
I suppose the next thing to do is to write a compiler of PArray() decompilations that would allow me to write nested arrays out to a text file and then read them back in. One day.