Once
upon a time, not so long before the video-games era, people needed the
command-line and knowledge of esoteric commands like _examine_,
_look_, _take_, _drop_, _go south_ etc. to
get into the mysterious worlds of dungeons &
dragons. If you have nostalgia to the heroic times of text-based
adventure games (nowadays called IF for _interactive fiction_),
there is a short message : get Inform(ed)! Here’s a
slightly longer message for those who have a mac running OSX and want to
know the quickest way to get to a screen like 
and start
playing Christminster (or another of 300 IF-games) (if you’re on a
different system, things will be just as simple but you’ll have to find
it out yourself starting from the Inform-Z
machine page). step 1 : Get a
copy of an inform installation and expand it to get an
Inform-folder and place this in your Home-folder. step 2
: Go in the Finder to Inform/Games/MyGame1 and double click on
the _MyGame1.command_ file. A Terminal window will open and exit
and you will see that a new file appeared in the Folder :
_MyGame1.z5_. Double click it and a warning message will appear
that this is the first time you will open _Zoom_, tell it’s ok
and Zoom will launch and you can play your first (though primitive)
Inform game! step 3 : If you want to play other
games (such as Christminster), go to the Z-
code archive and pick one of the 346 games. For example, click on
the minster.z5 link and the file will download to your
Desktop. Place it in the Inform/Games folder (not necessary) double
click it and you should see the above wellcoming message. That’s it,
start playing. step 4 : If you don’t know how to
play such games, there are excellent tutorials
available on the Inform site.
Tag: games
A quick reply to some of the comments
to the lulu/neverendingbooks post.
_Are they also
responsible for the graphical design in your books ?_ No! In fact it
was one of the more pleasant experiences of the last couple of weeks to
develop our own format, LaTeX-style and covers. The usual gang had their
say in all of this but it is only fair to say that Jan did most of the work. We developed
the cover-concept (that is, macro shots of games in duotones and placing
of titles etc) by trial and error. Jan is responsible for the
photo-shoot, I did choose the shots to be used and did the initial
coloring and placing of titles and left the final tweaking to Jan, who
did some lay-out work before. We, at least, are happy with the
result… As mentioned before, the LaTeX-style sheets were made
using the
memoir package.
_Who is responsible for trying to sell
the book, you or them?_ I dont think we are doing great efforts to
try to sell the books, yet. Up to now, you can only get to the
book-sites via this blog or via my homepage. Lulu claims that they will only make
money if we do… and as this is clearly sales-talk (they make money
on every book they print) it involves no (or a very small) financial
risk on our part. Anyone who wants to have a copy of one of our books,
orders them at Lulu, they print it and ship it to you. But beware! They
have several shipping options and for most of them it costs you more to
get them shipped than to buy the books… In fact, that was the main
reason why we didnt put the URL online before we had two volumes out.
The reason being that if you buy for over 25dollars you can have them
shipped via their “SuperSaver” option, that is, shipping is free (but
probably slow). But, based on my own experience it works well (I ordered
a few copies of book 1 via SuperSaver and another one via their
InternationalShipment and got the free SuperSaver package a day before
the costly other shipment…). Our real investment is that we have
bought ISBN-numbers for the books (at a price of 35dollars/book) and
hope to earn this back from a small royalty we get from each book (the
Lulu-rule is that they get 25% of any royalties you set). Even though we
are not entirely happy with the distribution process we opted for this
series for an unusual book-format making it handy and fun to use (the
square 7.5 x 7.5 inch format is very pleasing to read and the
coil-binding makes it extremely handy to lay flat on the table). So we
view this series as a student-edition of the books and we keep them as
cheap as possible. At a later stage it may happen that we will also have
a library-edition of the books which will have global distribution
(meaning that you can order them via Amazon or your local bookshop). For
this to work, you have not so much freedom in your book-format and can
only have regular binding. Besides, buying such a global-ISBN is more
costly and will make this edition (a lot) more expensive. But, as you
can see from the picture, the books get printed and shipped and look
VERY nice. In fact, of the few copies I ordered, I had to hand out
already two because some people just liked the feel and touch of it. I
think, people will only gradually be willing to buy their own copy when
(1) they have glanced through a copy at some meeting or seminar and (2)
if more volumes come out and they have a greater choice in bying 2
volumes to get free shipping. On this last issue : already three people
have expressed interest in writing a book in our series. My own hunch is
that the next book out will have to do with Poisson noncommutative
geometry and will have a macro shot of a war-game on its cover (authors
can give suggestions for which games they want on their cover), curious
how this will work out…
_How many have you sold so
far?_ Well, not enough so far to get our ISBN-investment back…
But, once again, I think it will take some time for people to trust the
series enough to buy a volume or two. In the first week we made the URL
available we sold 16 books, so if you want to increase our sales-index
please do by going to this
page for the first volume and to this page for the second
volume. But perhaps it is easier to bookmark the lulu/neverendingbooks if
you want the latest news on the series. I”ll keep you posted on our
sales via this page. If you buy a book and like the result, please tell
others about it (or even better, let them see and feel the copy.
Hopefully you will get it back…)
Before I'm bogged down by the changes let me
return to the snortGO
puzzle. Recall that in snortGO black and white take
turns in placing a Go-stone on the board respecting the rule that no
stones of opposite colour may be adjacent. Javier is right that snortGo
with an empty starting board having an odd number of rows and columns is
a first player's win (place your first stone on the central spot and
respond to your opponent's moves by reflecting them along the
center).
Still, one can compose realistic end-game problems (as
in the previous snortGo post where the problem was : prove that the position is a first
player's win and indicate a winning move for both black and white).
To start the analysis let us remove all spots which are unavailable for
both players (as depicted in the top picture). Some of the remaining
spots are available to just one player (the central free spots and the
two in the top left corner). One counts that black has 5 such central
spots and white 4 (including the top left corner). So, all the genuine
action is happening in the three remaining corner regions for which one
can calculate the exact value following the rules of combinatorial game
theory where bLack is playing Left and white Right (so the free
spots for black add up to +5 whereas those for white add up to -4). It
is pretty easy to work out the exact values of the corner subgames
To find the value of the total game we have to sum up these
values which can either be done by hand (use this and this to get
started and use the inductive rule $G+H = \\{ G^L+H,G+H^L \\vert
G^R+H,G+H^R \\}$) or using combinatorial game suite to
verify that this sum is equal to $\\{ \\{ 3 \\vert 2 \\} \\vert -1 \\}$
which is a fuzzy game (that is, confused with zero or a first
player's win). To find the actual winning moves just try out the
Left (bLack) and Right (white) options in the corner games to find out
that there is a unique winning move for white and there are just 2
winning moves for bLack, all indicated in the pictures below.
Noam D. Elkies is a
Harvard mathematician whose main research interests have to do with
lattices and elliptic curves. He is also a very talented composer of
chess problems. The problem to teh left is a proof game
in 14 moves. That is, find the UNIQUE legal chess game leading to the
given situation after the 14th move by black. Elkies has also written a
beautiful paper On Numbers
and Endgames applying combinatorial game theory (a la Winning
Ways!) to chess-endgames (mutual Zugzwang positions correspond to zero
positions) and a follow-up article Higher Nimbers in pawn
endgames on large chessboards. Together with Richard Stanley he wrote a
paper for the Mathematical Intelligencer called The Mathematical
Knight which is stuffed with chess problems! But perhaps most
surprising is that he managed to run his own course on Chess and
Mathematics!
COL is a map-coloring game invented by Colin Vout.
Two players Left (bLack) and Right (white) take turns in coloring the
map subject to the rule that no two neighboring regions may be colored
the same. The last player to be able to move wins the game. For my talk
on combinatorial game theory in two weeks, I choose for a simplified
version of COL, namely COLgo which is played with go-stoned on a
(partial) go-board. Each spot has 4 neighbors (North, East, South and
West). For example, the picture on the left is a legal COLgo-position on
a 5×5 board. COL is a simple game to illustrate some of the key features
of game theory. In sharp contrast to other games, one has a general
result on the possible values of a COL-position : each position has
value $z$ or $z+\\bigstar$ where $z$ is a (Conway)-number (that is, a
dyadic integer) and where $\\bigstar$ is the fuzzy game {0|0}. In
the talk I will give a proof of this result (there are not so many
results in combinatorial game theory one can prove from scratch in 50
minutes but this is one of them). Of course, to illustrate the result I
had to find positions which have counter-intuitive values such as 1/2.
The picture on the left is an example of such a position on a 5×5 board
but surely one must be able to find 1/2-positions on a 4×4 board
(perhaps even on a 3×3?). If you have an example, please tell me.
On a slightly different matter : I used the psgo.sty package in LaTeX to print the (partial)
go-boards and positions. If I ever write out the notes I’ll post them
here but they will be in Dutch.
The
game of sprouts is a two-person game invented by John Conway and Michael Paterson in 1967 (for some
historical comments visit the encyclopedia). You just need pen and paper to
play it. Here are the rules : Two players, Left and Right, alternate
moves until no more moves are possible. In the normal game, the last
person to move is the winner. In misere play, the last person to move is
the loser. The starting position is some number of small circles called
“spots”. A move consists of drawing a new spot g and then drawing two
lines, in the loose sense, each terminating at one end at spot g and at
the other end at some other spot. (The two lines can go to different
spots or the same spot, subject to the following conditions.) The lines
drawn cannot touch or cross any line or spot along the way. Also, no
more than three lines can terminate at any spot. A spot with three lines
attached is said to be “dead”, since it cannot facilitate any further
action.
You can play sprouts online using this Java applet.
There is also an ongoing discussion about sprouts on the geometry math forum. Probably the most complete
information can be found at the world game
of sprouts association. The analysis of the game involves some nice
topology (the Euler number) and as the options for Left and Right are
the same at each position it is an impartial game and the outcome
depends on counting arguments. There is also a (joke) variation on the
game called Brussels sprouts (although some people seem to miss the point
entirely).
Some years ago I invented some variations
on sprouts making it into a partizan game (that is, at a given
position, Left and Right have different legal moves). Here are the rules
:
Cold Antwerp Sprouts : We start with n White
dots. Left is allowed to connect two White dots or a White and bLue dot
or two bLue dots and must draw an additional Red dot on the connecting
line. Right is allowed to connect two White dots, a Red and a White dot
or two Red dots and must draw an additional bLue dot on the connecting
line.
Hot Antwerp Sprouts : We start with n
White dots. Left is allowed to connect two White dots or a White and
bLue dot or two bLue dots and must draw an additional bLue dot on the
connecting line. Right is allowed to connect two White dots, a Red and a
White dot or two Red dots and must draw an additional Red dot on the
connecting line.
Although the rules look pretty
similar, the analysis of these two games in entirely different. On
february 11th I’ll give a talk on this as an example in
Combinatorial Game Theory. I will show that Cold Antwerp Sprouts
is very similar to the game of COL, whereas Hot Antwerp Sprouts resembles SNORT.
As I am going to give a talk on Combinatorial Game Theory early
next month I have to update my rusty knowledge of canonical forms of
two-person game positions, their temperature theory and the like. As
most of the concepts in this field are recursive they are hard to work
out by humans but easy for computers. So it is nice to have a good
program to use. I remember that David Wolfe wrote a couple of years ago the Gamesman Toolkit but it seems he has taken it off
his website. Still, you can get it from the Software released by Michael Ernst page. So,
download the games.tar.gz-file and uncompress it on your Desktop.
Then do the following
cd Desktop/games sudo make sudo cp games /usr/bin/ /usr/bin/games
to get it up and
running (for documentation of how to use it see the Gamesman
Toolkit-paper above. But, it seems that as of July 2003 there is a much
better alternative around : the Combinatorial Game Suite of Aaron Siegel. It is an open source Java-program so it
runs on many platforms (including Mac OSX). Here is the way to get it
going : first download it and you will get a
cgsuite-0.4-folder on your desktop. Then type
cd Desktop/cgsuite-0.4 java -jar cgsuite.jar
and after a few
questions (including whether you want to be on the mailing list of the
project) the program starts up. It is very well documented with an
on-line manual which I have to read over the coming
days…
What then is all this WarWalking, WarDriving,
WarChalking and so on? In particular, why the aggressive
War-word in them ? From what I learned, the historical origin of
these terms comes from the 1983 movie “War Games” in which a
kid sets up his modem to dial numbers until it finds a computer to hack
leading inevitably to the US-army in total panic. This hobby created the
phrase WarDialing. In analogy, a person driving around in a car
with a laptop in search for wireless networks is said to be
WarDriving, if (s)he is on foot it is clearly WarWalking.
Because of the aggressive nature of the War-subword some people have
re-engineered an explanation :
WAR = Wireless
Access Reconnaissance
so let us hope this acronym
will catch on. Now then, what is WarChalking ? It was invented by
Matt Jones and the idea is that a WarWalker should write a symbol in
chalk on the wall nearest to the discovered Access Point describing its
nature (see picture on the left) : the first sign depicts an open
node, the next a closed one and the last one is a node with
WEP-protection (btw. WEP=Wired Equivalent Privacy). A lot
of people seem to take this fairly serious, there is even a webpage warchalking.org devoted to it on which you can
find a lot more information. And as warchalking was originally British,
there had to be also an American site containing among other things a not
that active forum. Further, the unofficial HOW-TO of WarDriving may be
interesting. To me it all sounds as an excuse to buy a
GPS-receiver and a
laptop…
We
have two old Macintosh Classics in perfect condition : one is the
first Mac-computer I bought back then and the other is one i adopted
when the mathematics department moved from UIA to our present place and
the secretary wanted to throw it away. But what can we do with them???
Well there seems to be a lot of potential : for instance you can turn
them into a linux-box of sorts, or you can get them to access the internet, some even claim they can be
turned into a webserver. And I think I once saw a page telling
how one could run OS X on a MacClassic (in fact really using it as an
external terminal to a working iMac) but I can\’t find the URL right
now. To me all this seems to be a bit pathetic, why use these nice
little boxes for something they can hardly handle and for which we do
have better equipmet around? So, what shall we do with those two
boxes?
Why not just do the things we used to do with
them back then : playing games (who did not play lemmings on a Classic?
or gnuChess), HyperCard applications, I even wrote a fair number of
TeX-files on a Classic. But as they have a harddisk of only 80Mb we have
to make choices, or dont we? Well, not really as I still have an old
SCSI 2Gig harddrive laying around (at the time 2 gigabytes seemed to be
an enormous amount of space and admit it, compared to 80Mb it is
enormous). So here is the plan : connect these two Classics via a
SCSI-cable to the externed 2 GB harddisk and load the disk with all
interesting stuff one can still find for 68k Macs.
Luckily there is a marvelous place for all these programs on the
web : the UMICH Archive! I will download whatever I find
interesting via normal means (that is an ordinary iMac) and dump it onto
the external HD so we can use the two Classic-boxes mainly to play games
(and there is a huge number of them on the archive). If you have better
uses for them, please let me know…
Some interesting URLs for low-end Macs :
– The
pure-mac Olden section
– Jag\’s house where older macs still
rock
– The Kids domain Black and White Mac Shareware page
and
all links contained in them.
– The
pure-mac Olden section
– Jag\’s house where older macs still
rock
– The Kids domain Black and White Mac Shareware page
and
all links contained in them.
(Added january 6th) I
found the URL for turning a MacClassic into an extra terminal Controlling Mac OS X With A Mac Plus (or other Classic
Mac)