Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10 5/26/83; site ihuxr.UUCP
Path: utzoo!linus!philabs!cmcl2!floyd!vax135!ariel!houti!hogpc!houxm!ihnp4!ihuxr!lew
From: lew@ihuxr.UUCP
Newsgroups: net.math
Subject: Re: surprize quiz
Message-ID: <627@ihuxr.UUCP>
Date: Fri, 9-Sep-83 17:09:13 EDT
Article-I.D.: ihuxr.627
Posted: Fri Sep  9 17:09:13 1983
Date-Received: Sat, 10-Sep-83 20:52:04 EDT
Organization: BTL Naperville, Il.
Lines: 31

Here's my explanation of the "surprise quiz" paradox. I think it
is a paradox of the same ilk as "this statement is false".

I would restate the teachers announcement as follows:

---------------------------------

I am going to give a quiz, subject to two conditions:

	1) It will be given during class one day this term.

	2) At no time prior to the quiz will it be possible
	   to infer from these conditions that the quiz will
	   be given on a certain day.


---------------------------------
I say that the paradox is now genuine. That is, it is impossible
for the teacher to fulfill these conditions. The self-referential
character of condition 2) is evident, and provides the key to the
paradox.

This paradox had a much bigger impact on me than others I've seen.
I find it hard to extricate the logical structure from my judgement
of what my real expectations would be if the teacher made the
announcement.

What if the teacher said, "I'm giving a quiz tomorrow, but you don't
know this." ???

	Lew Mammel, Jr. ihuxr!lew