ConwayLife.com

Posted: **August 25th, 2017, 6:04 pm**

'Block pusher' doesn't work in the viewer.

Posted: **August 25th, 2017, 7:16 pm**

drc wrote:'Block pusher' doesn't work in the viewer.

Thanks. Fixed in Beta 7. The new paragraph after the pattern had an extra four spaces in front of it, in the original text version. That seems to be one of the few formatting mistakes that makehtml.sh fails to complain about, but still has trouble handling.

Link to shiny new Beta #7 multipage HTML
Link to Beta #7 single-page HTML

Here's Beta 7 in text format. No doubt that wasn't the last problem -- please keep hunting!

[attachment "Release 26 of Life Lexicon, Beta 7, 7pm -- "bumper", "stable pseudo-Heisenburp", "HF" alias, minor fixes" removed -- see Release 8 in a later post]

Today I added a definition for "stable pseudo-Heisenburp", along with a pile of pN bumpers. The number of terms is definitely over a thousand now, and I think over twelve hundred if you count aliases. Errors might be more likely in the new material, but I bet there's still an anachronism or two hiding in old definitions also...

Posted: **August 26th, 2017, 1:21 am**

The single page Beta 7 with LifeViewer added is here.

Note the conversion script just looks for <pre> ... </pre> blocks which it assumes contains patterns. There are 5 cases where this is not true:

Herschel conduit
LifeLine
pseudo still life
spaceship
still life

To make sure they don't get a "Show in Viewer" button simply change both <pre> and </pre> for those definitions to <pre > and </pre > (basically add a space before the >) before running the conversion script.

Posted: **August 26th, 2017, 1:45 am**

This script will convert the multi-page Lexicon to use LifeViewer:

Code: Select all

#! /bin/sh
# Add LifeViewer to the multi-page Life Lexicon
# converted files go into a "conv" subdirectory

# define input and output file names
output1=lex1.html
output2=lex2.html
convdir=conv

# create the conv subdirectory
mkdir -p $convdir

# loop over each input file
for input in lex*.htm
do
   # insert the LifeViewer plugin into the head section
   cat $input | sed 's@</head>@<meta name="LifeViewer" content="viewer pre 150">\n<script src="lv-plugin.js"></script>\n&@' > $output1

   # add a show in viewer button to each pattern
   cat $output1 | sed 's@<pre>@<div class="viewer">\n<button type="button" onclick="updateViewer(this);return false;">Show in Viewer</button>\n&@' > $output2
   cat $output2 | sed 's@</pre>@&\n</div>\n@' > $convdir/$input
done

# copy in the css and image file
cp lifelex.css at.gif $convdir

# copy in the LifeVewer js file
cp lv-plugin.js $convdir

# tidy up
rm -f $output1 $output2

You should run it in a folder containing the multi-page Lexicon files to which you'll need to add a copy of the LifeViewer plugin, lv-plugin.js.

Posted: **August 26th, 2017, 4:09 am**

How about definitions for "adjustable spaceship", "engineered spaceship" and "engineerable spaceship"?

Posted: **August 26th, 2017, 7:34 am**

The definition for "crystal" is missing an "of":

Life Lexicon wrote: [...] this gives a crystal which forms a pair beehives for every 11 gliders which hit it.

Posted: **August 26th, 2017, 7:35 am**

This still life should probably be filed under "bi-loaf":-

Code: Select all

x = 6, y = 6, rule = B3/S23
b2o$o2bo$obobo$bobobo$2bo2bo$3b2o!

Posted: **August 26th, 2017, 7:52 am**

muzik wrote:How about definitions for "adjustable spaceship", "engineered spaceship" and "engineerable spaceship"?

Well... I'd certainly consider the first two, and even the yet-another-bi-loaf, if something showed up in the very near future that looked like this:

Code: Select all

:engineered spaceship:  Blah blah blah, {blah blah} blah blah {blah}.  Blah blah.

:adjustable spaceship:  Blah blah, {blah blah blah}.  Blah blah {blah} blah blah.

:bi-loaf:  This term has been used in at least four different senses...
[but is that really true?  Who's been talking about the Easter-egg bi-loaf lately?]
[pattern in ASCII format with 8-space indent]

I'm just plain out of time for generating new definition text myself. There are still several non-Lexicon things left on my to-do list for Golly 3.0.

The distinction between "engineered" and "engineerable" has always seemed way too subtle to me, and not just to me... and you yourself have agreed not to use "engineerable" as a category, if I'm understanding right. I'm not sure anyone but you has ever used "engineerable" successfully in a sentence -- I'd have to stop and think before every time I used it, and so I've stubbornly avoided the term. Really it just seems to mean "adjustable" anyway.

There are definitions in Release 26 already for "elementary", "macro-spaceship", and "self-constructing" and "self-supporting". I totally agree that those last two terms are ones that I have promoted and few other people have picked up, but those were the terms for which I knew how to write clear definitions, and ... um... Life isn't fair sometimes.

Mostly in this project I've tried to be good and only define terms that other people besides me have picked up and used in discussions. However, there are a few other cases that I'm not even going to list specifically when I really desperately needed a name for a concept, to be able to write other definitions concisely. Ultimately, anyone who objects to my choice of terms is more than welcome to go ahead and build the next Lexicon update...!

EDIT: Heading for Beta 8 now -- so much for lucky number 7. Will do the full rebuild and put it online let's say at the end of the day today, maybe fifteen hours from now or so.

Besides items mentioned above, there are some bad links in the intro sections, and a formatting problem with :snacker:. Also while patching some omissions in :self-supporting: I noticed that the :Caterpillar: entry still said it was the only one constructed so far (though it contradicted itself later). And :spiral growth: was out of date and had a trivial typo in it. These entries now read:

Code: Select all

:Caterpillar:  A {spaceship} that works by laying tracks at its front end.  The first example constructed was a p270 17c/45 spaceship built by Gabriel Nivasch...
[no other changes]

:spiral growth:  A {self-constructing} pattern built by Dave Greene in August 2014 that uses four {universal constructor}s (UCs) arranged in a diamond to build four more UCs in a slightly larger diamond.  This was the first B3/S23 pattern that exhibited spiral growth.  Much smaller versions have now been constructed using the {single-channel} construction toolkit.

:self-constructing:  A type of pattern, generally a {macro-spaceship}, that contains encoded construction information about itself, and makes a complete copy of itself using those instructions.  The {Gemini}, {linear propagator}, {spiral growth} patterns, {Demonoid}s and {Orthogonoid} are examples of self-constructing patterns.  Self-constructing spaceships often have trivially adjustable speeds.  In many cases, the direction of travel can also be altered, less easily, by changing the encoded {construction recipe}.  Compare {self-supporting}, {elementary}.

:self-supporting:  A type of pattern, specifically a {macro-spaceship}, that constructs {signal}s or {track}s or other scaffolding to assist its movement, but does not contain complete information about its own structure.  Examples include the Caterpillar, {Centipede}, {half-baked knightship}, {waterbear}, and the {Caterloopillar}s.  {Caterpillar} has been used as a general term for self-supporting spaceships, but it is not very appropriate for the HBKs.  In general a self-supporting pattern cannot be trivially adjusted to alter its speed or direction.  The variable speeds of the HBKs and the Caterloopillars are exceptions, but their direction of travel is fixed, and a specific Caterloopillar can't be made to change its speed without completely rebuilding it.  Compare {self-constructing}, {elementary}.

:macro-spaceship:  A {self-constructing} or {self-supporting} {spaceship}, such as the {Caterpillar}, {Centipede}, {half-baked knightship}, {waterbear}, {Demonoid}, {Orthogonoid}, and {Caterloopillar}.  Engineered spaceships of these types tend to be much larger and more complex than {elementary} spaceships.

Posted: **August 26th, 2017, 10:44 am**

Here's the current-as-of-right-now ASCII version of Beta 8. Theoretically it doesn't have any of the errors in it that anyone has mentioned to me so far. No doubt it will be removed and replace with a later greater up-to-dater version by the end of the day, so download it and criticize it quickly...!

Lexicon-release26-beta8a.txt: Provisional ASCII version of Release 26 Beta 8. The "a" means there will probably be a "b" soon --; (638.59 KiB) Downloaded 361 times

Posted: **August 27th, 2017, 1:22 am**

Release 26 Beta 8 is online. The links from previous posts still work, but I can relabel them and give them more exciting colors:

dvgrn wrote:Link to shiny new Release 26 Beta 8 multipage HTML
Link to Release 26 Beta 8 single-page HTML

We're about out of time for adding anything else, so thanks very much to everyone who has sent in missing terms -- I got quite a few by email as well as the ones posted higher up on this thread. There are several hundred new terms defined (or aliased), and it looks like the length of the text Lexicon has gone up by well over 50%.

(That last statistic may not be such a good thing, though -- if concise definitions were the goal, I may have missed the target occasionally.)

I'm still interested in hearing about typos and anachronisms and other factual errors, if anyone runs across anything. Running through the full build process for the Lexicon is too time-consuming to do again before Tuesday, but I could probably check in a few absolute last-minute changes directly to the affected HTML files, if it comes to that.

Posted: **August 27th, 2017, 3:24 am**

dvgrn wrote: I'm still interested in hearing about typos and anachronisms and other factual errors, if anyone runs across anything.

Some typos:

:25P3H1V0.1
- "minimumm" -> "minimum"
:arm
- "For a alternate" -> "For an alternate"
:Callahan
- "The glider from the southeast can be supplied by a Fx77..." -> "an Fx77..."
:cap
- "It can also be easily be stabilized" -> "It can also be easily stabilized"
:dependent conduit
- "... emitting its first natural glider, This is ..." -> "... glider. This ..."
- "... where a conduit?output Herschel..." -> "... a conduit-output Herschel..."
:freeze-dried
- "... is a constellaton..." -> "... is a constellation..."
:harvester
- "... refers to the fact the it produces..." -> "... fact that it produces..."
:H-to-MWSS
- "... October 2015, which convertes an input..." -> "... which converts an..."
:lightspeed wire
- "... for various things,but..." -> "...things, but..."
:p8
- "with a mnimum" -> "minimum"
:pentoad (p5)
- "... then another Z-hexomino can can be ..." -> "Z-hexomino can be"
:smoking ship
- "... turn or duplicate the them, ..." -> "... duplicate them, ..."
:torus
- "... obtaining an toroidal ..." -> "... obtaining a toroidal"
:univseral
- "... programmed to be construct itself, ... " -> "... to construct itself, ..."
- "as are needed to build a :1G seed:." -> " a {1G seed}."
:zweiback (p30)
- "A smaller version using using ..." -> "A smaller version using ..."

Posted: **August 27th, 2017, 5:41 am**

dvgrn wrote:I'm still interested in hearing about typos and anachronisms and other factual errors, if anyone runs across anything.

Here's a few:

The definitions of 25P3H1V0.1 and 25P3H1V0.2 need to be switched (with minor corrections, because they refer to each other). These names come from Heinrich Koenig's database where they are correctly labeled. Somehow they got mixed up when added to the wiki. The wiki also needs to be updated.
In light of the above, the "spaceship" definition needs to be corrected to list 25P3H1V0.1 as the first c/3 spaceship to be found. It should also probably be mentioned in the "c/3 spaceship" definition that 25P3H1V0.1 is the first known ship of this speed.

You never used Dean Hickerson's update to the "volatility" definition. Anyway, his update is now outdated, because Josh Ball found a p5 oscillator with volatility 1. Here is a corrected entry:

Code: Select all

:volatility:  The volatility of an {oscillator} is the size (in cells) of its {rotor} divided by the sum of the sizes of its rotor and its {stator}.  In other words, it is the proportion of cells involved in the oscillator which actually oscillate.  For many periods there are known oscillators with volatility 1, see for example {Achim's p16}, {figure-8}, {Kok's galaxy}, {mazing}, {pentadecathlon}, {phoenix}, {relay}, {smiley} and {tumbler}.  Such an oscillator of period 3 was found in August 2012 by Jason Summers.
   .........*.*.....*...*.....*.*.
   ........*...*....*...*....*...*
   .........*.......*...*.......*.
   ...........**.**.*...*.**.**...
   .................*...*.........
   ..........*...*.........*...*..
   ........*.*.................*.*
   ...............................
   ........*...................*..
   .......**..................**..
   .......*...................*...
   .....*..*................*..*..
   *....*..............*....*.....
   ****.**.***.........****.**.***
   ***.**.****.........***.**.****
   .....*....*..............*....*
   ..*..*................*..*.....
   ...*...................*.......
   ..**..................**.......
   ..*...................*........
   ...............................
   *.*.................*.*........
   ..*...*.........*...*..........
   .........*...*.................
   ...**.**.*...*.**.**...........
   .*.......*...*.......*.........
   *...*....*...*....*...*........
   .*.*.....*...*.....*.*.........
The smallest period for which the existence of such statorless oscillators is undecided is 7. There are oscillators with volatility arbitrarily close to 1 for all but finitely many periods, because of the possibility of feeding the gliders from a {true} period n {gun} into an {eater}.
     The term "volatility" is due to Robert Wainwright.  See also {strict volatility}.

Under the definition of "true" there are some gun periods missing (57, 58, and 61). I actually suggest a small table for the gun credits, or to eliminate the credits entirely. Here is an example of the table:

Code: Select all

----------------------------------
Period Discoverers            Date
----------------------------------
20     Matthias Merzenich May 2013
       Noam Elkies
22     David Eppstein     Aug 2000
       Jason Summers
24     Noam Elkies        Jun 1997
30     Bill Gosper        Nov 1970
36     Jason Summers      Jul 2004
40     Adam P. Goucher    Mar 2013
       Matthias Merzenich
       Jason Summers
44     David Buckingham   Apr 1992
45     Matthias Merzenich Apr 2010
46     Bill Gosper            1971
48     Noam Elkies        Jun 1997
50     Dean Hickerson     Oct 1996
       Noam Elkies
       David Buckingham
54     Dieter Leithner    Jan 1998
       Noam Elkies
       David Buckingham
55     Stephen Silver     Oct 1998
56     Dieter Leithner    Jan 1998
       David Buckingham
       Noam Elkies
57     Matthias Merzenich
58     'Thunk'            Apr 2016
       Matthias Merzenich
       Chris Cain
59     Adam P. Goucher    Dec 2009
       Jason Summers
60     Bill Gosper        Nov 1970
61     Luka Okanishi      Apr 2016
----------------------------------

If you wish to remove any of the extra names, you should leave the top name for any given period, as that is the first person to actually build an explicit gun.

25-cell quadratic growth: should say "in October 2014", not "on October 2014".
wickstretcher: should include a mention of the c/5 diagonal wickstretcher (found Jan 2011 by Matthias Merzenich) and the c/5 orthogonal wickstretcher (found Mar 2013 by Matthias Merzenich).

There are a number of places where it seems like there should be links to other terms in the lexicon (e.g. most spaceships don't seem to link to the "spaceship" definition). I'm not sure if you had any plans to address this.

Edit: I changed "Dietrich Leithner" to "Dieter Leithner" in the gun table, as that seems to be what he preferred. Most of the lexicon uses "Dieter", but there are 4 entries that use "Dietrich": {boojum reflector}, {reflector}, {staged recovery}, and {switchable gun}. These 4 should probably be changed for consistency.

Similarly under {half-baked knightship}, "Adam Goucher" should be replaced with "Adam P. Goucher".

Posted: **August 27th, 2017, 6:00 am**

Sokwe wrote:[*] The definitions of 25P3H1V0.1 and 25P3H1V0.2 need to be switched (with minor corrections, because they refer to each other). These names come from Heinrich Koenig's database where they are correctly labeled. Somehow they got mixed up when added to the wiki. The wiki also needs to be updated.

Done (wiki update, that is).

(If anyone would like to look this over to make sure I didn't accidentally introduce any mistakes -- these two ships have always confused me...)

Posted: **August 27th, 2017, 12:10 pm**

@rowett and @Sokwe, thanks for doing great last-minute reviews. I'm working through the suggestions and should be able to get them all in.

I'm especially happy about the 25P3H1V0.1 vs. 25P3H1V0.2 catch -- that could have gotten a lot of people mixed up if it hadn't been repaired. In writing the definitions I remember being confused by which one was which for a while, and then being confused by why I had been confused, and then just taking the LifeWiki's word for it...!

Sokwe wrote:It should also probably be mentioned in the "c/3 spaceship" definition that 25P3H1V0.1 is the first known ship of this speed.

It's good that I went and looked at that entry again, too. I removed the sentence

A spaceship moving diagonally at an angle of 45 degree cannot travel at a speed of c/3, but it is likely that c/3 {knightship}s exist, though none have yet been found.

... noticing as I did so that "degree" should have been "degrees" ...! It's hard to calculate a consistent single-number speed for oblique ships without resorting to sines and cosines, and even there you'd have to do something weirder than the usual definition. Otherwise you'd end up with gliders going either "c/2" or "sqrt(2)c/2". I was sure I'd taken that part out before, but I must have been editing the wrong file (sadly this is not unheard of, despite all my attempts to avoid it).

Sokwe wrote:There are a number of places where it seems like there should be links to other terms in the lexicon (e.g. most spaceships don't seem to link to the "spaceship" definition). I'm not sure if you had any plans to address this.

Not for this round, I think. I did a quick search and saw lots of {spaceship} links, and I'm not about to try anything silly like a global search-and-replace for plain " spaceship ", since I'm sure that was only an example. Will have to either re-read the whole document and add links manually, or write a script to suggest making links for each first instance of a known term in each definition -- other than the term being defined... Even that isn't so simple, because different forms of words can be linked.

Probably it's just something to do manually. But the links are only a convenience in any case -- the big thing is to get the definitions in there.

Posted: **August 27th, 2017, 12:17 pm**

dvgrn wrote:... noticing as I did so that "degree" should have been "degrees" ...! It's hard to calculate a consistent single-number speed for oblique ships without resorting to sines and cosines, and even there you'd have to do something weirder than the usual definition. Otherwise you'd end up with gliders going either "c/2" or "sqrt(2)c/2".

I do apologize in advance for straying off-topic, but isn't the speed for ships just based on a king-wise move metric? I.e., if a ship moves at speed (u,v)/pc, then its single-number speed is max(u, v)/pc. This matches how both diagonal and orthogonal speeds are measured, and is consistent with how information propagates, at least in Life-like CAs using the Moore neighborhood.

Posted: **August 27th, 2017, 2:02 pm**

Okay, let's add another link to the pile to keep things interesting. Added an :extruder: link along with the other suggested changes, since I had to recompile again anyway. Getting down to the wire now, though --!

Link to even shinier Release 26 Beta 8+ multipage HTML
Link to Release 26 Beta 8+ single-page HTML
Link to Release 26 Beta 8+ single-page ASCII

Apple Bottom wrote:
dvgrn wrote:... noticing as I did so that "degree" should have been "degrees" ...! It's hard to calculate a consistent single-number speed for oblique ships without resorting to sines and cosines, and even there you'd have to do something weirder than the usual definition. Otherwise you'd end up with gliders going either "c/2" or "sqrt(2)c/2".
I do apologize in advance for straying off-topic, but isn't the speed for ships just based on a king-wise move metric? I.e., if a ship moves at speed (u,v)/pc, then its single-number speed is max(u, v)/pc. This matches how both diagonal and orthogonal speeds are measured, and is consistent with how information propagates, at least in Life-like CAs using the Moore neighborhood.

Yes, absolutely. But I'm not sure there's a decent reason any more to drop half of the information in (u,v), just so that we can arbitrarily classify a spaceship with a single-number speed. If multiple oblique macro-spaceships end up in the same single-number speed category, they'll most likely be in the same (u,v)c/p category too.

-- Or if they're not, then their having the same single-number speed will be kind of a meaningless accident, not implying that the two have anything much in common. Seems like the same is true for elementary knightships... does it really help anything to lump hypothetical (2/1)c/6 knightships in with orthogonal c/3s?

None of the context about (2,1)c/6, therefore "c/3" if you drop the smaller component of the speed vector was provided in the sentence I dropped, so it seemed likely to be more confusing than helpful.

The point about information propagation speed is a good one... but not good enough to make me want to encourage common use of single-number speed measurements, I think. A (1000,998)c/[a billion] oblique ship can't be usefully put into the same category as a (1000, 2)c/[a billion] oblique ship, though they'd both get the same single-number c-over-a-million speed.

I'd have to think about it some more, but I think we could probably build both of those ships now -- the first would be a sneaky modification to a Demonoid, where the second would be a modified Orthogonoid. Very different (though analogous) animals --!

The notation with parentheses is annoying, but avoiding that minor awkwardness by cavalierly throwing away important information... seems to me to be just inviting confusion, I guess.

Posted: **August 27th, 2017, 2:37 pm**

Long time no see...

2c/3 wire: In 2017 Martin Grant observed that the 2c/3 signal can be split successfully into two half-signals that can be separated from each other by an arbitrary number of ticks.

I suspect this is known before, especially regarding this oscillator:

Code: Select all

x = 28, y = 29, rule = B3/S23
obo3b2o$2obobo2bo$3bob2obo$3o5bob2o$o5b3obo$b3o7bo$6b5o$b3o$bo5b6o$3b
2obo6bo$4bobo2bob3o$2bobobobobo5bo$2b2o2bobobob5o$6bobobo$7b2obo2b6o$
10bobo6bo$10bobo2bob3o$11b2obobo5bo$14bobob5o$14bobo8bo$13b2obo2b7o$
16bobo$16bobo2bob3o$17b2obobo2bo$20bobo$20bobob4o$19b2obo4bo$23b3o$25b
2o!

But I'll see if I can validate that.
Antstretcher The example doesn't really "stretch" ants, but I get the idea.
:c/10 spaceship There is a typo: 4×+2 (perhaps 4×n+2?)

:colour-changing See colour of a glider. The period-8 reflector shown in reflector is colour-changing, as are its p4/5/6/7 and higher-period versions.

There isn't a reflector shown in
"reflector". Perhaps change it to p8 reflector?
:copperhead 'zdc' -> 'zdr'

:sidesnagger The second glider comes too soon, crashing the pattern.

Edit: Oops, a little too late :?
Edit2: The next version number should be 10 ;)

Edit3: I'm not sure what the p5 t-nose is for, as there are p5 pipsquirters, but I reduced it to something less humongous:

Code: Select all

x = 39, y = 41, rule = B3/S23
8bo$8bo20bo$7b3o19bo$28b3o$5bo2bo2bo$5bobobobo8b2o4bo2bo2bo4b2o$4bo7bo
7bobo3bobobobo3bobo$4bo2bobo2bo9bo2bo7bo2bo$4o3bobo3b4o5b4o2bobo2b4o$
4bo7bo15bobo$2b4o5b4o7b3o9b3o$2b2o3bobo3b2o7bo2bob2ob2obo2bo$4b2o5b2o
10bobo7bobo$6b5o9b3o2bobo3bobo2b3o$o3b2o5b2o3bo3bo4b3o3b3o4bo$2obobo2b
o2bobob2o5b4o7b4o$bo3bobobobo3bo5b2o13b2o$o2b2obobobob2o2bo7b2o7b2o$3o
bobo3bobob3o4b3o2bo5bo2b3o$b2obobobobobob2o4bo2bo3bo3bo3bo2bo$b2obo2bo
bo2bob2o5bobobo2bobo2bobobo$5bobobobo8b2obobob2ob2obobob2o$b5obobob5o
8b2obo3bob2o$7bobo17bo3bo$b2o2b2obob2o2b2o11b2ob2o$bo2bobo3bobo2bo$4bo
3bo3bo$4b9o$3bo9bo$2b2o2b2ob2o2b2o$3bobobobobobo$3b2o2bobo2b2o$3bob2o
3b2obo$3bobo5bobo$o3bo7bo3bo$4o3bobo3b4o$4b3o3b3o$2b2o3b3o3b2o$bo2b2o
5b2o2bo$2bobob5obobo$3bo4bo4bo!

Posted: **August 27th, 2017, 3:25 pm**

dvgrn wrote:The point about information propagation speed is a good one... but not good enough to make me want to encourage common use of single-number speed measurements, I think. A (1000,998)c/[a billion] oblique ship can't be usefully put into the same category as a (1000, 2)c/[a billion] oblique ship, though they'd both get the same single-number c-over-a-million speed.

Oh, yes, I'd definitely not want to encourage people to start using single-number speeds for oblique ships -- at least not without mentioning the slope as well! I was just looking for a workable definition, i.e. one that doesn't clash with the established way of measuring the speeds of orthogonal and diagonal ships.

(Re: sines and cosines and square roots, BTW, while these would help measure a ship's "true" (Euclidean) speed, there'd still be some potential for confusion... a (3,4)c/50 ship and a (14,48)c/500 ship would move at the same overall speed of c/10, yet again, they're clearly quite different.)

The notation with parentheses is annoying, but avoiding that minor awkwardness by cavalierly throwing away important information... seems to me to be just inviting confusion, I guess.

Definitely agreed, though I personally don't think e.g. "(2,1)c/6" is annoying -- it's self-explanatory and unambiguous.

Posted: **August 27th, 2017, 3:58 pm**

Scorbie wrote:Edit: Oops, a little too late
Edit2: The next version number should be 10

No way. I'm not admitting that there are large numbers of changes left, so I'm up to Beta 8++...! Working on the three typos you pointed out now.

Scorbie wrote:Edit3: I'm not sure what the p5 t-nose is for, as there are p5 pipsquirters...

Not in the Lexicon there aren't. I think this is one of the better p5 pipsquirters --

Code: Select all

        .........*.........
        .........*.........
        ...................
        ...**..*.*.*..**...
        ...*...*****...*...
        ....***.....***....
        ......*.....*......
        ..*****..*..*****..
        ..*..*..*.*..*..*..
        ...*.....*.....*...
        ***.............***
        *.................*

but the diagonal clearance to its spark is much lower than the p6 and p7 squirters, so it really can't be used in the same kinds of places. If no one ever uses or talks about p5 pipsquirters, then are they really a thing to be defined? I suppose they are, but I'm not sure I'll get to it for this round.

Similarly, I think the p5 T-nose is humongous specifically to support the nice pointy forward end without the eaterish forward projections.

Posted: **August 27th, 2017, 10:10 pm**

{true}: In the credit table I accidentally forgot to add the date for the p57 gun. It should be April 2016.
{non-trivial}: Should say "contains at least one cell that oscillates at the full period."
{omniperiodic}: Maybe replace "If we insist that the oscillator must contain a cell oscillating at the full period" with "If we insist that the oscillator be {non-trivial}".
{strict volatility}: List the periods with known strictly-volatile oscillators. They are 1, 2, 3, 5, 6, 8, 13, 15, 22, 30, 33, and 177. Possibly include a composite-period example, such as this p22 found by Nicolay Beluchenko on 4 March 2009:
Code: Select all
```
x = 16, y = 16, rule = B3/S23
11b2o$10bobo$2bo5bo4bo$2ob2o2b2obobo$o7bo3bo$bobo2$2b3o7bo$3bo7b3o2$
12bobo$3bo3bo7bo$3bobob2o2b2ob2o$2bo4bo5bo$3bobo$3b2o!
```
Edit: examples of strictly-volatile oscillators that are in the lexicon are figure eight, Kok's galaxy, smiley,
and pentadecathlon

Edit: some more things:

{reflector}: the sentence "All known stable reflectors are very slow." should be removed.
{pre-pulsar}: the last sentence is incorrect. Consider changing to "The pre-pulsar was also a vital component of the first known p26 and p47 oscillators."

Posted: **August 28th, 2017, 2:00 pm**

dvgrn wrote:
Scorbie wrote:Edit: Oops, a little too late :?
Edit2: The next version number should be 10 ;)
No way. I'm not admitting that there are large numbers of changes left, so I'm up to Beta 8++...! Working on the three typos you pointed out now.

Yeah :) I wasn't too serious about the versioning. Nice work on the lexicon all along. It's much more comprehensive and up to date. I see you did a lot there...

dvgrn wrote:
Scorbie wrote:Edit3: I'm not sure what the p5 t-nose is for, as there are p5 pipsquirters...
Not in the Lexicon there aren't. I think this is one of the better p5 pipsquirters --
Code: Select all
        .........*.........
        .........*.........
        ...................
        ...**..*.*.*..**...
        ...*...*****...*...
        ....***.....***....
        ......*.....*......
        ..*****..*..*****..
        ..*..*..*.*..*..*..
        ...*.....*.....*...
        ***.............***
        *.................*
but the diagonal clearance to its spark is much lower than the p6 and p7 squirters, so it really can't be used in the same kinds of places. If no one ever uses or talks about p5 pipsquirters, then are they really a thing to be defined? I suppose they are, but I'm not sure I'll get to it for this round.

Similarly, I think the p5 T-nose is humongous specifically to support the nice pointy forward end without the eaterish forward projections.

Ah, I see. The lexicon's t-nose may stay for now. Still, I wouldn't use that big one personally as in jslife there are also less intrusive p5 pipsquirters (with clearance similar to that of the t-nose) with more reasonable sizes. I, as well, have never seen a use case for the p5 pipsquirter.

Posted: **August 31st, 2017, 7:27 am**

Something for the next point version--

:still life: has a table with the numbers of (strict) still lifes up to 32 bits, but the sentence leading up to the table only gives credits up to 24 bits:

Life Lexicon wrote: Still lifes have been enumerated by Conway (4-7 bits), Robert Wainwright (8-10 bits), Dave Buckingham (11-13 bits), Peter Raynham (14 bits) and Mark Niemiec (15-24 bits). The resulting figures are shown below.

I think Simon Ekström and Nathaniel Johnston should be credited there. (Also, a pointer to A019473 in the OEIS might not be amiss.)

Posted: **August 31st, 2017, 1:27 pm**

Apple Bottom wrote:Something for the next point version--

:still life: has a table with the numbers of (strict) still lifes up to 32 bits, but the sentence leading up to the table only gives credits up to 24 bits...

As usual, following the trail of interlocking terms turned up several other omissions that seemed worth fixing. Here are three new definitions and two revised ones. Please let me know if anything doesn't seem accurate:

Code: Select all

:pseudo still life:  The definition of {strict still life} rules out such {stable} patterns as the {bi-block}.  In such patterns there are dead cells which have more than 3 neighbours in total, but fewer than 3 in any component still life.  These patterns are called pseudo still lifes.  Mark Niemiec and others have enumerated the pseudo still lifes up to 32 bits; these figures are shown below; see also {https://oeis.org/A056613}.  Included in the final number is the unique 32-bit {triple pseudo} still life.
        --------------
        Bits    Number
        --------------
         8           1
         9           1
        10           7
        11          16
        12          55
        13         110
        14         279
        15         620
        16        1645
        17        4067
        18       10843
        19       27250
        20       70637
        21      179011
        22      462086
        23     1184882
        24     3068984
        25     7906676
        26    20463274
        27    52816265
        28   136655095
        29   353198379
        30   914075620
        31  2364815358
        32  6123084116
        --------------
     A {stable} pattern whose live cells are not connected by adjacent dead cells where birth is suppressed by overpopulation.

:quad pseudo:  A {still life} that can be broken down into four {stable} pieces but not into two or three.  This term may refer to the following 34-bit pattern, found by Gabriel Nivasch in July 2001, or any similar pattern with the same property.
        ........**.
        ...**.*..*.
        ...*.**.*..
        ........**.
        ...*.**...*
        .***.**.**.
        *.......*..
        .***.**.*..
        ...*.*.*...
     As a consequence of the Four-Colour Theorem, there can be no analogous objects requiring decomposition into five or more pieces.  By convention, patterns like this and the {triple pseudo} are considered to be {pseudo still life}s, not {strict still life}s.  As of August 2017 it has been shown that no quad pseudo patterns exist with 32 or fewer bits, but a 33-bit pattern with this property may theoretically still be found.

:strict still life:  A {still life} that is either a single connected {polyplet}, or is arranged such that a {stable} smaller pattern cannot be formed by removing one or more of its {island}s. For example, {beehive with tail} is a strict still life because it is connected, and {table on table} is a strict still life because neither of the {table}s are stable by themselves.  See also {triple pseudo}, {quad pseudo}.
     Still lifes have been enumerated by Conway (4-7 bits), Robert Wainwright (8-10 bits), Dave Buckingham (11-13 bits), Peter Raynham (14 bits), Mark Niemiec (15-24 bits), and Simon Ekstrom and Nathaniel Johnston (25-32 bits).  The resulting figures are shown below; see also {https://oeis.org/A019473}.  The most recent search by Nathaniel Johnston has also confirmed that the {triple pseudo} pattern found by Gabriel Nivasch is the only such still life with 32 bits or less.  It is therefore included in the pseudo still life count and not in the table below.
        --------------
        Bits    Number
        --------------
         4           2
         5           1
         6           5
         7           4
         8           9
         9          10
        10          25
        11          46
        12         121
        13         240
        14         619
        15        1353
        16        3286
        17        7773
        18       19044
        19       45759
        20      112243
        21      273188
        22      672172
        23     1646147
        24     4051711
        25     9971377
        26    24619307
        27    60823008
        28   150613157
        29   373188952		
        30   926068847		
        31  2299616637		
        32  5716948683
        --------------

:still life:  Any {stable} pattern, usually assumed to be finite and nonempty.  For the purposes of enumerating still lifes this definition is, however, unsatisfactory because, for example, any pair of blocks would count as a still life, and there would therefore be an infinite number of 8-bit still lifes.
     For this reason a stricter definition is often used, counting a stable pattern as a {strict still life} only if its {island}s cannot be divided into two or more nonempty sets both of which are stable in their own right.  If such a subdivision can be made, the pattern is a {pseudo still life}.
     In rare cases bove a certain size threshold, a pattern may be divisible into three or four stable nonempty subsets but not into two.  See the 32-bit {triple pseudo} (32 bits) and the 34-bit {quad pseudo} for examples.
     All still lifes up to 18 bits have been shown to be {glider constructible}.  It is an open question whether all still lifes can be incrementally constructed using glider collisions.  For a subset of small still lifes that have been found to be especially useful in {self-constructing} circuitry, see also {Spartan}.

:triple pseudo:  The following pattern, found by Gabriel Nivasch in July 2001.  It is unique among 32-bit {still life}s in that it can be broken down into three {stable} pieces but not into two.  The term may also refer to any larger {stable} pattern with the same property.  See also {quad pseudo}.
        ......**
        ..*.*..*
        .*.**.*.
        .*....**
        **.**...
        ...**.**
        **....*.
        .*.**.*.
        *..*.*..
        **......

These will find their way into the "official" Release 26 Life Lexicon at http://www.conwaylife.com/ref/lexicon/, probably in a week or three -- and will eventually also sneak into Golly at some opportune moment.

Posted: **August 31st, 2017, 4:31 pm**

dvgrn wrote:As usual, following the trail of interlocking terms turned up several other omissions that seemed worth fixing. Here are three new definitions and two revised ones. Please let me know if anything doesn't seem accurate:

Looks good to me! But I think the last sentence in the :pseudo still life: entry was supposed to have been the first...?

Code: Select all

:pseudo still life:  The definition of {strict still life} rules out such {stable} patterns as the {bi-block}.  In such patterns there are dead cells which have more than 3 neighbours in total, but fewer than 3 in any component still life.  These patterns are called pseudo still lifes.  Mark Niemiec and others have enumerated the pseudo still lifes up to 32 bits; these figures are shown below; see also {https://oeis.org/A056613}.  Included in the final number is the unique 32-bit {triple pseudo} still life.
     [table omitted]
     A {stable} pattern whose live cells are not connected by adjacent dead cells where birth is suppressed by overpopulation.

Also: the definition of a still life as any stable (finite, nonempty) includes constellations, but these are not considered still lifes of any kind, are they? Perhaps instead of "pattern", it should say "object".

(Then again, maybe it's just me who's confused about the intricacies of different classes of stable patterns. This is still my best current understanding -- but it might still be wrong, or (worse) oversimplified.)

These will find their way into the "official" Release 26 Life Lexicon at http://www.conwaylife.com/ref/lexicon/, probably in a week or three -- and will eventually also sneak into Golly at some opportune moment.

Excellent!

Posted: **August 31st, 2017, 5:17 pm**

Apple Bottom wrote:... I think the last sentence in the :pseudo still life: entry was supposed to have been the first...?

Bother, no, it's a little more complicated than that. That last sentence was an unfinished thought -- I wanted to get a link to {constellation} in there somewhere. How about this?

Code: Select all

:pseudo still life:  A {stable} pattern whose live cells are either immediately adjacent to each other, or are connected into a single group by adjacent dead cells where birth is suppressed by overpopulation.
     The definition of {strict still life} rules out such stable patterns as the {bi-block}.  In such patterns there are dead cells which have more than 3 neighbours in total, but fewer than 3 in any component still life.  These patterns are called pseudo still lifes, and have been enumerated up to 32 bits, as shown in the table below.
        [table omitted]
     Attribution of these counts is given in {strict still life}; see also {https://oeis.org/A056613}.  The unique 32-bit {triple pseudo} still life is included in the last count in the table.
     If a stable pattern's live cells plus its overpopulated dead cells do not form a single mutually adjacent group, the pattern is usually referred to as a {constellation}.  It is also technically a {still life} in the general sense, but is neither "pseudo" nor "strict".

Apple Bottom wrote:Also: the definition of a still life as any stable (finite, nonempty) includes constellations, but these are not considered still lifes of any kind, are they? Perhaps instead of "pattern", it should say "object".

(Then again, maybe it's just me who's confused about the intricacies of different classes of stable patterns. This is still my best current understanding -- but it might still be wrong, or (worse) oversimplified.)

I think you have things pretty much right, in terms of common usage.

I've been working from that original Life Lexicon definition of "still life" that you mentioned, and thought I had made everything work out okay. "strict" and "pseudo" are specific sub-categories, but "still life" can also be a constellation of well-separated (strict and pseudo) still lifes. In this sense, "still life" is used as a short form of "still life constellation".

If that's acceptable, then I think no changes are really needed to your ASCII-art diagram -- it's just that "still life" is a little-used synonym for "stable pattern", at the very top. There doesn't seem to be anything in the definitions of "strict still life" and "pseudo still life" that requires that any still life must be either one or the other...?

By the way, I was originally thinking of including "quasi still life" as a term in Release 26 --it definitely seems like a potentially useful term. But it doesn't really seem as if it's gotten into general use enough yet, to make a good Lexicon entry.

ConwayLife.com

Life Lexicon update -- now Release 29, 2 July 2018

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