Re: Objects and Relations

> > > > what is a relational expression for the string bob?
> > > { (0, 'b'), (1, 'o'), (2, 'b') }
> > Is the following relationally equivalent?
> > { (2, 'b'), ('b', 0'), ('o', 1) }
>
> No. The parenthesized elements within the braces can be reordered;
> the elements of the ordered tuple within the parentheses cannot.

I assume you would say that sets with unordered elements are the foundation. If so, how does this let one create a new type of set with ordered elements? What is the proof that the new type of set is firmly based on the foundation? What is the logic/reationale that allows one to go from sets with unordered elements to sets with ordered element? What logic prevents one from creating another new type of set with his own rules? Received on Wed Jan 31 2007 - 03:33:23 CET