Upside down E was Re: Mathematical Symbols

[Baker, John]

        It's easier to understand what Barbara Need is saying if you imagine a capital F instead of a capital E.  The right-side-up F has bars in the middle and top of the letter, pointing to the right.  What would an upside down F look like?  If the paper is simply rotated on a vertical axis (i.e., the paper remains flat on the desk and is turned around, or the viewer walks to the other side of the desk), the two bars of the F, now at the middle and bottom of the letter, will point to the left.  But I think of an upside-down F as having bars that point to the right, just as they do when the letter is right-side-up.

John Baker


-----Original Message-----
From: Laurence Horn [mailto:laurence.horn at YALE.EDU]
Sent: Thursday, February 20, 2003 12:03 AM
To: ADS-L at LISTSERV.UGA.EDU
Subject: Re: Upside down E was Re: Mathematical Symbols


At 9:42 PM -0600 2/19/03, Barbara Need wrote:
>
>My first thought was: wouldn't an upside down E be identical to a
>right-side up E? But then I thought, when you look at someone's
>writing "upside down" it is the reversed E, because the writing is
>also right to left FROM YOUR PERSPECTIVE. But when I turn something
>upside down, I usually only rotate on a horizontal axis, not also on
>the vertical one. Is this the usual sense of turn something upside
>down?
>
I don't know; this is too complicated for me.  I write a
right-side-up E on a piece of paper and I turn the paper upside down
and I get an existential quantifier, not the E that I started with.
(Works with computer monitors too.)  Don't know from perspectives and
axes, but that's how I do it.

L