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Life Lexicon
Release 27, 2017 October 11
Single-page HTML version
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INTRODUCTION
This is a lexicon of terms relating to John Horton Conway's Game of Life.
An ASCII version and a multipage HTML version are also available.
This HTML version can be viewed either
with frames or
without frames.
This lexicon was originally compiled between 1997 and 2006 by
Stephen A. Silver, and was updated in 2016-17 by Dave Greene. See
below for additional credits.
The latest versions of this lexicon (both HTML and ASCII) should be available from the
Life Lexicon Home Page.
CREDITS
The largest single source for the early versions of this lexicon was a
glossary
compiled by Alan Hensel
"with indispensable help from John Conway, Dean Hickerson, David Bell,
Bill Gosper, Bob Wainwright, Noam Elkies, Nathan Thompson, Harold McIntosh,
and Dan Hoey".
Other sources include the works listed in the
bibliography at the
end of this lexicon, as well as pattern collections by
Alan Hensel
and
David Bell
(and especially Dean Hickerson's file stamp.l in the latter collection),
and the web sites of
Mark Niemiec,
Paul Callahan,
Achim Flammenkamp,
Robert Wainwright
and
Heinrich Koenig.
Recent releases also use a lot of information from Dean Hickerson's
header to his 1995
stamp file.
Most of the information on recent results is from the discoverers
themselves, or from Nathaniel Johnston's excellent resources at
http://www.conwaylife.com, including both the LifeWiki and the
discussion forums.
The following people all provided useful comments on earlier releases
of this lexicon: David Bell, Nicolay Beluchenko, Johan Bontes, Scot
Ellison, Nick Gotts, Dave Greene, Alan Hensel, Dean Hickerson, Dieter
Leithner, Mark Niemiec, Gabriel Nivasch, Andrzej Okrasinski, Peter Rott,
Ken Takusagawa, Andrew Trevorrow and Malcolm Tyrrell.
The format, errors, use of British English and anything else you
might want to complain about are by Stephen Silver -- except that for
post-Version 25 definitions, everything besides the British English
may well be Dave Greene's fault instead.
COPYING
This lexicon is copyright © Stephen Silver, 1997-2017.
It may be freely copied and/or modified as long as due credit is given.
This includes not just credit to those who have
contributed in some way to the present version (see above),
but also credit to those who have made any modifications.
LEXICOGRAPHIC ORDER
I have adopted the following convention: all characters (including spaces)
other than letters and digits are ignored for the purposes of ordering the
entries in this lexicon.
(Many terms are used by some people as a single word,
with or without a hyphen, and by others as two words.
My convention means that I do not have to list these in two separate places.
Indeed, I list them only once, choosing whichever form seems most
common or sensible.)
Digits lexicographically precede letters.
FORMAT
The main thing to note about the format of the HTML version is that
all keywords are preceded by a colon. For example, entering :foo in
the dialogue box of your browser's Find command will take you straight
to the definition of the first word beginning with "foo"
(or at least it would if there were any).
This is the recommended way of finding a
particular definition when there is no link to click on.
The diagrams in this lexicon are in a very standard format.
You should be able to simply copy a pattern, paste it into
a new file and run it in your favourite Life program.
If you use
Andrew Trevorrow and Tomas Rokicki's Golly
then you can just paste the pattern directly into the Life program.
Diagrams are generally restricted to size 64x64 or less.
Most definitions that have a diagram have also some data in brackets
after the keyword.
Oscillators are maked as pn (where n is a positive integer),
meaning that the period is n (p1 indicates a still life).
Wicks are marked in the same way but with the word "wick" added.
For spaceships the speed (as a fraction of c, the speed of light),
the direction and the period are given.
Fuses are marked with speed and period and have the word "fuse" added.
Wicks and fuses are infinite in extent and so have necessarily been
truncated, with the ends stabilized wherever practical.
SCOPE
This lexicon covers only Conway's Life,
and provides no information about other cellular automata.
David Bell has written articles on two other interesting cellular automata:
HighLife (which is similar to Life, but has a tiny replicator) and
Day & Night (which is very different, but exhibits many of the same
phenomena).
These articles can be found on
his website.
ERRORS AND OMISSIONS
If you find any errors (including typos) or serious omissions, then please
email b3s23life@gmail.com with the details.
As of August 2017 this email address is monitored by Dave Greene.
NAMES
When deciding whether to use full or abbreviated forms of forenames
I have tried, wherever possible, to follow the usage of the person concerned.
QUOTE
Every other author may aspire to praise;
the lexicographer can only hope to escape reproach.
Samuel Johnson, 1775
DEDICATION
This lexicon is dedicated to the memory of Dieter Leithner,
who died on 26 February 1999.