Date: May 2, 2013 10:42 PM
Author: Louis Talman
Subject: Re: Based on the quadrilateral tree

On Thu, 02 May 2013 18:01:25 -0600, Gary Tupper <> wrote:

> If there is a comparable advantage to using the restrictive definition,
> I do not know it.

The restrictive definition allows its advocates to be certain that an
isosceles trapezoid is not a parallelogram.

- --Louis A. Talman
Department of Mathematical and Computer Sciences
Metropolitan State University of Denver