Meaning of Q.E.F.

Date: 8/20/96 at 11:18:17
From: Anonymous
Subject: Meaning of Q.E.F.

What does Q.E.F. mean?  I've seen it in Euclid's Elements (Book I, 
postulate 1, and other places), along with Q.E.D.  It seems to be 
things he has stated in sort of hand-wavy, "this is just how it's 
done," postulates, as opposed to something he had deduced directly 
from what he had.

-David :)

Date: 8/20/96 at 12:44:18
From: Doctor Sarah
Subject: Re: Meaning of Q.E.F.

Hi David -

You're on the right track.  As you know, Q.E.D. is the abbreviation 
for the Latin _quod erat demonstrandum_, "Which was to be 
demonstrated."  Similarly, Q.E.F. is the abbreviation for _quod erat 
faciendum_, "Which was to be done."   Your description of where it's 
found thus seems quite appropriate.

-Doctor Sarah,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/