Re: Relation Schemata vs. Relation Variables

Keith H Duggar wrote:
> Brian Selzer wrote:
> > For instance, consider the following states for a
> > relation describing people's marital status, and a
> > transition constraint that says: Single people can't
> > become Divorced:
> >
> > Current Proposed
> > Jane Jones Married Jane Jones Married
> > Jane Smith Single Jane Smith Divorced
>
> Please express this constraint using relational calculus.
> I'm particularly interested to see how "people" and
> "become" are expressed.

Forgive this bump, but I'm a little curious. Was my above question irrelevant or tangent or ignorant in some way? Are such constraints usually specified in relational calculus? Thank you in advance to anyone offering guidance.

• Keith -- Fraud 6