wrote in message news:<5895-417451C9->...
> I can prove that "Happy Days" and "Laverne & Shirley" are set in the
> same universe as "Star Trek".
>
> charachters share the same universe.
Is this one of those series of crossovers
things, connecting shows A to B to C to D by
using characters who appeared in two shows?
That's not a very strong proof, since the same
character might have counterparts in multiple
universes; if character X from show A appears
on show B, that can just mean that the
universes of A and show B have character X
in common.
Consider things other than characters. Does,
say, Fawlty Towers have to be in the same
universe as MASH because Basil Fawlty once
mentioned the Korean War? No, it could just
be two universes, both of which had a Korean
War. And the same for characters.