HDTenEightyP/NetNews huggingface dataset:
From: guckes@math.fu-berlin.de (Sven Guckes)
Subject: Re: UTILITIES
Originator: guckes@medusa
Organization: Free University of Berlin, Germany
Date: Sat, 15 Aug 1992 17:54:53 GMT

From: tjgerman@53iss6.Waterloo.NCR.COM (Trevor German)
> Take a pencil and draw three houses, then draw three utility
>   companies, say water gas and electric. Now the puzzle is to draw 
>   a line from each house to each utility without crossing any line.

From: jimhsu@athena.mit.edu (Jimmy M.D. Hsu)
>I don't think it's possible.  Unless you're
>thinking of folding the paper or some other
>technicality.  Try this:
>Five aliens wish to shake hands.  Draw five
>spots on the paper, anywhere you like.  These
>aliens have four limbs (tentacle-like) and
>really enjoy linking up in groups of five.
>Well, along comes a scientist, and this
>scientist puts these five aliens under
>a microscope slide for study.  Since the
>slide is heavy, the amoeba-like aliens
>can't cross their tentacles.  So, try linking
>all five of these guys!  Good luck.  ;^p

The graph described by Trevor usually is denoted by "K_{3,3}"
and the one by Jimmy usually is denoted by "K_{5}".
I will use K3,3 and K5 as notations now.

Graphs that can be drawn on a plane are called "planar".
Both K3,3 and K5 are NOT planar!
To see this is very easy if you know about the theorem of Jordan.
But to prove that one isn't so easy.

As a matter of fact ALL non planar graphs contain a subgraph isomorphic
to a K3,3 or a K5.

Read all about it in some books about "Graph Theory" in your nearest
math library.
From: mueller@schaefer.math.wisc.edu (Carl Douglas Mueller)
Newsgroups: rec.puzzles
Subject: Re: Godel's Theorem
Keywords: Godel
Date: 22 Aug 92 20:17:25 GMT
Reply-To: mueller@schaefer.UUCP (Carl Douglas Mueller)
Organization: Univ. of Wisconsin Dept. of Mathematics

In article <1992Aug22.150550.6680@leland.Stanford.EDU> dgenr8@leland.Stanford.EDU (Tom Harding) writes:
>Is the following statement true or false?  Why?

    No.  It is not.  
>
>This statement has no proof.
>
>  -Tom Harding
                 Carl Mueller (mueller@math.wisc.edu)
Newsgroups: rec.puzzles
From: tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman)
Subject: Virtual reality puzzle
Date: 18 Aug 92 00:23:38 MDT
Organization: University of Utah, CompSci Dept


  It is the year 2056, and the first perfect virtual reality simulators
have hit the market.  So you buy one, bring it home, and plug into it.
After a few days of fighting orcs, swinging through jungles and living
on Jupiter making peace with aliens you decide to visit your wife.

  So you unplug it, walk around the house, looking under beds and in closets
until you realize she is at work.  She walks in the front door, and.....
you realize that you MIGHT STILL BE IN THE VIRTUAL SIMULATION.  The 
simulation is hooked into your house computer, which has been recording
everything for the past few years.  It also is hooked into the local
and global networks containing all the information about what is going on.
The vitual simulator could be simulating your real life- and you might
still be attached to it.  Even when you "unplugged" it merely simulated that.

  What is a sure way to know if you are in the real world or the virtual
one?  That is the puzzle.
Newsgroups: rec.puzzles
From: gblanken@magnus.acs.ohio-state.edu (Gerime P Blankenship)
Subject: Re: Homographs
Organization: The Ohio State University
Date: Mon, 17 Aug 1992 14:35:30 GMT

     How about these for a homograph that is a noun/adjective.
     Stable (a place for horses)
     Stable (what I am most of the time)
From: asymptot@sbe (Mike Mathews)
Newsgroups: rec.puzzles
Subject: Re: SSN puzzle
Keywords: primes, SSN
Date: 19 Aug 92 23:46:53 GMT
Organization: School of Business, California State University, Hayward

In article <chepan.714251286@gsusgi1.gsu.edu> chepan@gsusgi1.gsu.edu (Parthasarathy Nambi) writes:
>
>	I hope the following is *not* a stupid puzzle!!!!!
>
>
>
>	Assume that USA population is 250 million.
>
>	Assume also that everyone has a Social Security number
>	and also none of those start with 0 in the first digit.
>
>	How many people in the US have SSN which is also a prime?
>
>	P.Nambi

well, ignoring  the fact that my SSN *does* begin with a zero :-)

define a function f(x) where f(x)={number of integers < x which are prime}

then the answer should approximate (25/90)*(f(1,000,000,000)-f(100,000,000))
which I could calculate if I were near reference materials-

note that f(x) is a commonly used function in the study of prime numbers, but
it goes by a different name (totient?)

25/90 comes from 25mill./90mill. and can (obviously) be reduced to 5/18

cheers,
mike mathews
Newsgroups: rec.puzzles,talk.bizarre
From: spencer@phoenix.Princeton.EDU (S. Spencer Sun)
Subject: Re: rot13 word pairs
Reply-To: spencer@phoenix.princeton.edu (S. Spencer Sun)
Organization: Live Organ Transplants
Distribution: rec
Date: Wed, 19 Aug 1992 20:32:01 GMT

In article <1992Aug19.163910.7008@kakwa.ucs.ualberta.ca> of talk.bizarre, aaron@space.ualberta.ca writes:
>"nowhere" and "abjurer"

In article <schnitzi.714245207@eola.cs.ucf.edu> of rec.puzzles, schnitzi@cs.ucf.edu (Mark Schnitzius) writes:
>This is actually going on in talk.bizarre but
>belongs here.  What is the longest word that
>rot13's to another word?
>
>The best so far is "nowhere/abjurer".

OK, this may take all the fun out of it, but in our 98,294-word
/usr/dict/words at JvNC, nowhere/abjurer is the longest rot13 pair.
Here's how I figured it out (just a matter of using the right tools
:-) ):

1. tr < /usr/dict/words A-Z a-z | sort | uniq > dict.orig
2. tr < /usr/dict/words A-MN-Za-mn-z n-za-mn-za-m | sort | uniq > dict.rot13
3. cat dict.orig dict.rot13 | sort > dict.combined
4. uniq < dict.combined -d

Steps 3 and 4 could be performed in a single pipeline if desired.

Anyone have a bigger /usr/dict/words?

----------- The opinions expressed in this article are solely mine. -----------
<Insert lame attempt at disclaimer humor>
sss/PU'94 Dept of CS (spencer@phoenix.princeton.edu)/JvNCnet (spencer@jvnc.net)
Judgement comes from experience.  Experience comes from poor judgement.
Newsgroups: rec.puzzles
From: jimhsu@athena.mit.edu (Jimmy M.D. Hsu)
Subject: Re: UTILITIES
Organization: Massachusetts Institute of Technology
Date: Sat, 15 Aug 1992 06:53:52 GMT

Spoiler Alert!



















I don't think it's possible.  Unless you're
thinking of folding the paper or some other
technicality.  Try this:

Five aliens wish to shake hands.  Draw five
spots on the paper, anywhere you like.  These
aliens have four limbs (tentacle-like) and
really enjoy linking up in groups of five.
Well, along comes a scientist, and this
scientist puts these five aliens under
a microscope slide for study.  Since the
slide is heavy, the amoeba-like aliens
can't cross their tentacles.  So, try linking
all five of these guys!  Good luck.  ;^p


Amdee @ MIT

Nutation Nation   :<  :>
From: dodson@convex.COM (Dave Dodson)
Newsgroups: rec.puzzles
Subject: Re: WEST
Date: 18 Aug 92 22:02:04 GMT
Reply-To: dodson@convex.COM (Dave Dodson)
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
Originator: dodson@bach.convex.com
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In article <9817@ncrwat.Waterloo.NCR.COM> tjgerman@53iss6.Waterloo.NCR.COM (Trevor German) writes:
>
>	An aircraft sets off from city A in a straight line due west
>	at a ground speed of 250mph.  How long till it reaches city
>	B 2000 miles due west?  Both cities are in Canada.

The solution to this puzzle depends on what is meant by:

(1)	"sets off from city A in a straight line due west", and

(2)	"city B 2000 miles due west" of city A.

Normally, one would assume that (1) means "traveling on a great circle
route that leaves city A on a 270 degree heading", while (2) means that
"city A and city B have the same latitude".  With two different definitions
of "west" it is not surprising that the plane never reaches city B.

If we consider other definitions for (1) and/or (2), we might come up
with (2) meaning that city B is west of city A on an azimuthal projection
centered on city A, in which case the plane reaches city B in 8 hours.

Or maybe the navigator plots the plane's heading on a Mercator projection.

Or maybe the plane continues to fly a heading as if it were on a great
circle, but the wind changes and blows the plane north just the right
amount.  If the wind is straight out of the south, the plane reaches
city B in somewhat more than 8 hours as it is flying in a crosswind.

Or, since the earth is not a sphere, a great circle really does not
close on itself.  Thus after completing one "orbit" of the earth the
plane passes either east or west of city A.  In some cases, then, the
plane may reach city B after some number of "orbits".

Or an earthquake (12 or 15 on the Richter scale, I suppose) moves city
B southwardly while the plane is in flight.

The possibilities are endless.  Let's hear a few more.

P.S.  Isn't Canada on the metric system?  What is this "miles" stuff?

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

Dave Dodson		                             dodson@convex.COM
Convex Computer Corporation      Richardson, Texas      (214) 497-4234
Newsgroups: rec.puzzles
From: karr@cs.cornell.edu (David Karr)
Subject: Re: Swallows
Keywords: technicality
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Date: Wed, 19 Aug 1992 15:54:31 GMT

In article <1992Aug19.111443.9038@nntp.nta.no> stein@hal.nta.no (Stein Kulseth FBA) writes:
>A swallow(A) is flying south. It then spots another swallow(B) flying behind
>it, but some distance to the right on a parallell course due south. Ie:
>
>                       (A)
>- - - - - - - - - - - - => - - - - - - - - - - - -
>
>
>- - - - - - - - - => - - - - - - - - - - - - - - -
>                 (B)
>
>Now A wants to intercept B in order to pick up the latest swallow gossip.
>What change in direction should A make?
>
>Estimates of unknown speeds and estimates takes time. The earth is *flat*
>and the swallows may or may not be laden with coconuts

If the swallow (A) must make an instantaneous course correction
without having any time to observe the speed of (B), and that course
must be the correct interception course the first time, I think that
(A) has insufficient information to solve the problem.  Given only the
distance and bearing of (B), there are many possible interception
points depending on the relative speeds, and (A) cannot know which one
to head for.

However, if you will allow just a little extra time, there is a simple
and elegant way of matching courses, based on principles used by
people on boats:

<SPOILER>



(A) notes the relative bearing of (B), that is, what direction is (B)
from (A) relative to the direction in which (A) is headed.  (A) holds
his course for a while while observing (B) to see that (B) also appears
to be holding course (not turning).  Now if the relative bearing of
(B) is decreasing, i.e. (B) appears to be traveling to the left as
seen from (A) in (A)'s frame of reference, then (B) is going to go
ahead of (A).  Then, in the situation shown, (A) cannot intercept (B)
unless (A) speeds up.

On the other hand, if (B) appears to be traveling to the right, as seen
from (A), (B) is going to fall behind (A).  In this case, (A) should
turn a few degrees to the right, then fly a while on this new heading.
If (B) starts to get "ahead" now, then (A) turned too far and should
turn back to the left (but not all the way back onto the old course).

(A) continues to adjust his heading until he observes that (B) neither
moves to the right or the left in his frame of reference.  Then (A)
and (B) are on a collision course, and (A) will intercept (B).

Of course, in boating one more typically wants to AVOID the collision
course, hence the rule of thumb is different; one changes course only
if the other boat does NOT move to the right or left in your frame of
reference.  :-)

-- David Karr (karr@cs.cornell.edu)
From: strgh@warwick.ac.uk (J E H Shaw)
Newsgroups: rec.puzzles
Subject: Re: NUMBER CREATION USING FOUR "2"s
Date: 21 Aug 92 12:47:19 GMT
Organization: Computing Services, Warwick University, UK

In article <1992Aug21.021818.23556@pbhyf.PacBell.COM> skataba@pbhyf.PacBell.COM (Sam Atabaki) writes:
>Creating numbers using four "2"s and any of mathematical
>operators and symbols
>such as:                                 __
>          +, -, *, /, .(dot), ^(power), V   (square root),
>                          _
>          ! (factorial), .2 (decimal repeatition), ...
>
>
>      ********************************************************
>Unsolved numbers in the 0-99 range as of (8/20/92):
>
>                     37 38 39
...
Writing V for `square root of ..',

                        _    2
        38 = 2 + ((V(2/.2))!)

and

#define SPOILSPORT 1
plagiarising an idea from (I think) `Manifold', the old Warwick University
Maths magazine, if you allow logs:

        37 = -log log VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV(2+2)
                 2   2

(38 nested square roots).
In APL, of course, you can do 37 with just one 2.
#undef SPOILSPORT
                -- Ewart Shaw
-- 
J.E.H.Shaw,  Department of Statistics,  |  JANET:  strgh@uk.ac.warwick.cu
             University of Warwick,     |  BITNET: strgh%uk.ac.warwick.cu@UKACRL
             Coventry  CV4 7AL,  U.K.   |  PHONE:  +44 203 523069
yacc - the piece of code that understandeth all parsing
Newsgroups: rec.puzzles
From: mblum@chaos.cs.brandeis.edu (Cerebus)
Subject: Re: Virtual reality puzzle *spoilers?*
Organization: Brandeis University
Date: Thu, 20 Aug 1992 02:56:58 GMT

tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:
>  It is the year 2056, and the first perfect virtual reality simulators
>have hit the market.  So you buy one, bring it home, and plug into it.
>After a few days of fighting orcs, swinging through jungles and living
>on Jupiter making peace with aliens you decide to visit your wife.

>  So you unplug it, walk around the house, looking under beds and in closets
>until you realize she is at work.  She walks in the front door, and.....
>you realize that you MIGHT STILL BE IN THE VIRTUAL SIMULATION.  The 
>simulation is hooked into your house computer, which has been recording
>everything for the past few years.  It also is hooked into the local
>and global networks containing all the information about what is going on.
>The vitual simulator could be simulating your real life- and you might
>still be attached to it.  Even when you "unplugged" it merely simulated that.

>  What is a sure way to know if you are in the real world or the virtual
>one?  That is the puzzle.

Well, that depends on how much information you are assuming this
simulation could have access to.  If it couldn't, say, find out about
every little detail about your life, you could always just tell an
inside joke to someone who should understand it, and see if he or she
gets it.

If you assume the simulation can get every little piece of
information, you have but to wait until you pass out from: 1. lack of
sleep; 2. lack of drink; 3. lack of food.  Since sleeping, eating, and
drinking in a simulation would just be simulated, your actual body
wouldn't get the benefits from those activities, and so, if you were
living in a simulation, you couldn't stay conscious long if all these
were fake.  So you just need to do what seems to be eating, sleeping,
and drinking, and if, after a few days, everything feels fine, you're
in reality.

-- Matt
+------------------------------+------------------------------------------+
|  Matt "Matt" Blum            | Let's make George Bush the 33rd          |
|                              |     ex-President of the United States!   |
| mblum@chaos.cs.brandeis.edu  |                                          |
|                              | I am not politically incorrect.          |
|  (617)893-2820               | I am politically challenged.             |
+------------------------------+------------------------------------------+
Newsgroups: rec.games.chess,rec.games.board
From: connors@drutx.ATT.COM (ConnorsPA)
Newsgroups: rec.games.chess
Subject: Re: Rules of Chess
Date: 19 Aug 92 07:35:10 GMT
Organization: AT&T, Denver, CO

> Someone recently told me that there is a sort of Catch-22 situation
> in the rules of chess.
> 
> (1) As soon as checkmate occurs, the game is over.
> (2) If an illegal move is not called by the opponant before the
> 	end of the game, then the move must stand.

> So.  I pick my Queen up from wherever it happens to be on the board,
> slam it down somewhere else, completely illegally, creating a checkmate
> situation.

> Question:  Does this actually work?  And if it does, has anyone ever
> won a major prize doing it?

Yes, indeed, quite a few tournaments have been won by this means,
including a couple of Zonals in the 50's. Since a tournament being
decided in such a manner could only bring disrepute upon the organizers
and participants, these occasions have generally been hushed up, and
you will only find faked game-scores where this has happened.

If I remember rightly, the last event that this happened in
in modern times was in Russia, in the last round of Tatiana, 1965,
and it involved a young Garry Kasparov. Garry, playing Black,
and requiring only a draw to qualify for his next title, deliberately
chose the Petroff.

After:
	1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6
Garry was shocked to find that White (the up and coming Swimpovsky)
played:
	4. Qxf7 mate

After much all-around upset, and tears, the arbiter was simply forced
to accept that, according to the strict interpretation of the then rules,
White had won.

The rules for Soviet chess were changed after this (and, of course,
FIDE rubber-stamped the Soviet change). The reputation of the Petroff
improved, and people looked forward to a panic-free future.

They reckoned without Swimpovsky. Since the published tournament
bulletin had been doctored to show Swimpovsky winning by rather
stodgy and disgraceful positional means, Swimpovsky determined upon revenge.

The rules used to read: "If a player having the move touches
his own piece, he must move it."

In the first round of the very next tournament -- Musor, 1966 -- Swimpovsky,
as White, faced Garry in the first round.

Starting at a1, moving down to h1, and back to a2 via h2,
Swimpovsky calmly touched each and every one of his pieces.
And then moved each one. Garry faced a rather large development
disadvantage. But it was all in accordance with the precise
interpretation of the rules. The arbiter (for once being prepared)
quickly phoned in the situation to the Central Rules Committee
in Moscow. The rules were immediately modified by unanimous vote.
This was too late for Garry, who now did not even have the
possibility of copying Swimpovsky. (If you look up this game in
ChessBase today, all you will find is a fictitious game with
a Ponziani opening, Swimpovsky winning in 176 moves.)

Nowadays, all the rules of chess have been exhaustively
analyzed by computer, and no loop-holes exist. Or so they say.
But Swimpovsky has occasionally been seen with a rather strange smile.
From: malingka@rec/games/chessps.msu.edu (Richard Malingkas)
Newsgroups: rec.games.chess
Subject: Re: US Open - round 10 (correction)
Date: 15 Aug 92 04:31:22 GMT
Reply-To: malingka@cps.msu.edu (Richard Malingkas)
Followup-To: rec.games.chess
Distribution: usa
Organization: Dept. of Computer Science, Michigan State University
Originator: malingka@atlantic.cps.msu.edu

In article <1992Aug14.070402.11760@msuinfo.cl.msu.edu> malingka@cps.msu.edu (Richard Malingkas) writes:
>
>Results of the top 5 boards on round 11 (played Thur. Aug 13, 1992):
>Finegold - Kaidanov	: 0.5
>Tsemekhman - Kudrin	: 0-1
			 ^^^^^
The score should have been 1-0.
-- 
*----------------------*
  _Richard Malingkas__                      
  malingka@cps.msu.edu                 
*----------------------*
From: msc@watson.ibm.com (Murray Campbell)
Subject: Checkers match
Date: Thu, 20 Aug 1992 17:27:12 GMT
Disclaimer: This posting represents the poster's views, not necessarily those of IBM
Organization: IBM T.J. Watson Research Center

There is currently a match going on between Marion Tinsley (sp?),
who has been world checkers champion for many years, and
"Chinook", a checkers program out of the University of Alberta written
by a group headed by Jonathan Schaeffer.  The match is taking
place in London, England.  I heard that on Wednesday August 19,
Chinook managed to beat Tinsley to level the match at one win each
with 6 draws.  This is notable because Tinsley has lost only a
handful of games in his 40 year career, and has had no losses
in the past ten years.  The match is supposed to continue
until August 29, with a total of 40 games to be played.
Newsgroups: rec.games.chess
From: philip@spr.usask.ca (Tim Philip)
Subject: Re: Suggestions for chess program?
Organization: University of Saskatchewan, Saskatoon, Canada
Date: Mon, 17 Aug 1992 22:17:41 GMT


	Does anybody know where I can get MChess??  How about
	KnightStalker??

	Tim.
From: cc738@cleveland.Freenet.Edu (Teik-Meng Lee)
Newsgroups: rec.games.chess
Subject: CHESS SERVER?
Date: 19 Aug 92 15:25:31 GMT
Article-I.D.: usenet.1992Aug19.152531.1294
Organization: Case Western Reserve University, Cleveland, Ohio, (USA)


Dear All Chess Enthusiast;

  Could someone please tell me if there is a chess server that
I can log in to play with other people through the computer?
I know that there is a site for "GO".  

Thank you very much for reading. 

Please E-mail to me at: 

IN%"lee_tm@max.cc.denison.edu"

Teik-Meng Lee 
Denison University 
Newsgroups: rec.games.chess
From: ed@cbnewsl.cb.att.com (edward.m.hummel)
Subject: Re: US Open
Organization: AT&T
Date: Thu, 13 Aug 1992 01:16:39 GMT

In article schiller@tira.uchicago.edu (Eric Schiller) writes:
>I don't see any need to allow computers in normal
>tournaments, but I just see no need to stop organizers`
>from doing so. It is their money at risk, and they should
>be free to experiment to find the best formats.

If you really want to allow organizers to do whatever they want and let
the market determine their choice, you would recommended to permit them 
to allow humans to refuse to play computers.  Instead you no longer permit
the organizers this option.  I would have less of an objection if the
committee recommended that there be three types of tournaments
(C, NC and MC -- computer [optional pairing], no computers allowed,
Must-play computer [no refusal allowed]).  Was this option
considered by the committee?

>If so many people object to computers, then the new rules
>will benefit those who oppose computers, because people
>will refuse to play and eliminate events with computers.

I suppose the people who opposed Hitler should have been
glad to see him elected chancellor because the suffering
he would cause would encourage the world to eliminate him.
If something wrong is being done, it should be opposed.

>But I suspect that the complainants are a small but vocal
>minority.

If the committe made no attempt to find out what the CUSTOMERS
of the USCF wanted and you only "suspect" that the complainants
are a small minority, I have concerns about the way the committee
decides things.  Perhaps the committee sees the important customers
of the USCF to be the computer developers.  What exactly is the
charter of this committee?

>The odds of playing against a computer in a
>mid-size events are much lower than that of being paired
>with a real asshole. There are some fates worse than
>computers.

I've played a few "assholes" over the years, but I'd rather play
them than play a computer in a competitve tournament.  If someone
chopped off your hand you could be happy it wasn't your arm 
instead.

Ed Hummel