> I mentioned "SubSequence" because Slate implements those and renames
> SequenceableCollection to Sequence. What I was suggesting was that
> SequenceableCollection includes (sub-)sliceability or linearization
> capability, and that SubSequence be the slices themselves.

And again, I ask, how are those 'slices' any different than a 
sequencable collection anyways?

NB, any array can be stored as a linear 1D array with the appropiate 
choice of computing addresses/offsets into it.... ( nevermind storing 
binary trees as arrays w/o using pointers in C )

I still DON'T see the need?

A Collection of Collections is a 2D array, that can return a collection 
as a slice. One can slice and dice any way you want ( with the 
necessary code of course )...

Why add extra complexity where none is needed?

-Daniel