Subject: glossary

From: "Rick Snodgrass" <rts>
Date: Thu, 25 Feb 1993 11:48:24 MST

The definition of temporal element found in the glossary published in
SIGMOD Record contains the terms "time box" and "bitemporal
rectangle," which are undefined. I suggest the following changes.

1. Replace "finite union of n-dimensional time boxes" in the
definition of temporal element with "finite set of $n$-dimensional
chronons".

2. The definition of chronon be extended to allow $n$-dimensional
chronons.  This could be accomplished by adding this sentence to the
definition of chronon:

	"An $n$-dimensional chronon is a non-decomposable region
	 in $n$-dimensional time."

3. Replace "bitemporal rectangles" in the definition of temporal element
with "$n$-dimensional chronons".

-- Rick