Re: Relation Definition

dwolt wrote:
>
> By no means - this is much improved! Do you mind if I add these to the
> glossary?

By all means.

> I can guess what "domain" means here (a set), but would like that to be
> spelled out too at some point. There seem to be differences on what
> get tossed into the domain set -- does it have operators, for example?

The exact terminology varies a little. Strictly speaking a domain is a set of values where (1) these values must have a readable representation and (2) an equivalence relation is defined over these representations that says when they denote the same value. Next to that there may be predicates and operations defined over these domains such as a linear order or arithmetic operations. These operations are usually not seen as part of a domain since they may have different input domains and yet another output domain, but predicates over the domain such as the equality and order are sometimes seen as part of the domain itself. It's not really essential whether you do or not.

• Jan Hidders