Re: Theory Question--Two tables relating in more than one way?

> owner has at least one primary car, and may have others.

Following script models its with an experimental db (XDb3):

// Create person type and add to directory.
(CREATE type inst *person & dir item it)

// Create car type and add to directory.
(CREATE type inst *car & dir item it)

// Create predicate own.
(CREATE verb inst *own)

// Create john owns a chevette and a corvette.
(CREATE person inst *john)
(CREATE john own (CREATE car inst *chevette))
(CREATE john own (CREATE car inst *corvette))

// Deleting "john own chevette" makes corevette his primary car. Received on Tue Mar 01 2005 - 04:58:45 CET