Idea for new element: <transclusion />

[Oscar Levin]

We were chatting with someone (Cameron) at MathFest who is doing lots of interesting stuff with PreTeXt.  One of his ideas was to link together different pretext documents, say by including the theorem of one book in the prose of another.  There was also a recent request on discord for repeating a theorem later in the book (not in a knowl).

I think both of these are reasonable ideas, and could be solved with a #transclusion element.  These could be knowled or not.  With a ref or href, this could display the content of the transcluded element.  Some details would need to be worked out with cross document transclusion (much easier of the other document is pretext).

Does this seem like something worth thinking about more?