To let $ mathscr U: = (U delta) $ let be a separable metric space that is universal for all finite metric spaces, d. H. for every finite metric space $ mathscr X: = (X d) $ There
exists an isometric embedding of $ mathscr X $ in
$ \ mathscr U. $
Q: Is there a 0-dimensional subset?
$ C subset U $ in the $ mathscr U $ so that room
$ (C , \ delta | C ! Times ! C) $ is universal for all finite metric spaces?
The same applies to question
As long as I know, these are questions to open,