I am completely lost. I have a vague feeling that Rosa〇Barks Universe refers to something that includes some of the stories but not all of them, but I have no idea how to understand 〇. I guess the term means part of the Barks' universe that was selected and developed by Rosa, is it?
(I can type it because it happens to be a Chinese character, which means zero)
Let's say that "Barks universe" is for people regarding Barks stories (but not Rosa stories) as canon, like TitusMcDuck; "Rosa universe" is for people regarding Rosa stories (but not Barks stories) as canon, which is virtually nobody; and "Barks/Rosa universe", or "Rosa○Barks Universe", is for people ragrding both Barks stories and Rosa stories as canon.
Not to sound like a broken record, and I understand this is semantics to an extent, but I'd argue that what you are describing here are headcanons, not universes. The Barks universe exists, the Rosa universe exists (and contains within it most, but not all, elements of the Barks universe); whether you accept one or both as "real" defines your "headcanon", but has no bearing on the existence of the universes themselves. To illustrate the point more clearly, there is a DuckTales '87 universe, where Donald is in the navy, HD&L live with Scrooge, Webby and Launchpad are around, Beagle Boys are dissimilar, etc. None of this is "real" to me, but that doesn't change the fact that this self-contained universe exists. So nobody can object if one were to say they had a "Barks/Rosa headcanon", but when you say "Barks/Rosa universe" it implies something external which is outside the control of the reader (or other writers).
I do not know if it is what gooey98 intended, maybe that was involuntary...anyhow, as a mathematician, I do approve the notation "Rosa○Barks". It represents the composition of Barks(-) and Rosa(-), seen as functions. So, if you consider Disney's Universe as an argument of some sort, then Barks(Disney's Universe) represents the result of the action of Barks on this Universe, and Rosa(Barks(Disney's Universe)) the result of the action of Rosa on the latter. Rosa○Barks(-) is just a standard alternative notation for the composed function Rosa(Barks(-)).
Yup, I understood and approved of this notation...my only problem with it is that the symbol is not on my keyboard! So I'd have to "copy/paste" it all the time.
Yes, this is what I intended. Math jokes for the win.
I consider the stories of Bob Karp & Taliaferro, Al Hubbard & Dick Kinney and Floyd Gottfredson as canon to the Barks-Rosa universe, as long as they contradict them (like some Taliaferro strips which state that Scrooge's father was rich and was alive in 1912)