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Life Lexicon update

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Re: Life Lexicon update

Postby Apple Bottom » September 1st, 2017, 6:02 am

dvgrn wrote: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?


That looks fine to me.

dvgrn wrote: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...?


Yes, I think that's perfectly acceptable. So would it be correct to say that the unqualified term "still life" can, in common parlance, refer to both stable objects and stable patterns, depending on the context? (I have a distinct feeling I should take a look at the LifeWiki entry on still lifes again to make sure that its use of the term is consistent and in line with the Lexicon.)

(It's remarkable, BTW -- "still life" is such an intuitively accessible, easily understood term, yet the closer you look at it, the more it evades you.)

dvgrn wrote: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.


Well, it was coined by Mark Niemiec, so I'd say that's a point in its favor (appeal to authority, I know, but I think it's justified here). OTOH there's only a few uses of the term on e.g. this forum, so it might be best to defer inclusion to a later edition of the Lexicon.
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Re: Life Lexicon update

Postby dvgrn » September 1st, 2017, 8:32 am

Apple Bottom wrote:So would it be correct to say that the unqualified term "still life" can, in common parlance, refer to both stable objects and stable patterns, depending on the context?

Yup, context is important. I've personally used "still life" in this way, mostly when I'm distinguishing "still life constellation" from "P2 constellation".

It's good that the Lexicon definition is what it is, because otherwise a "quasi still life" wouldn't be a still life.

Apple Bottom wrote: ... there's only a few uses of the term on e.g. this forum, so it might be best to defer inclusion to a later edition of the Lexicon.

-- Well, here we are adding to the number of usage instances every time we bring the darn things up. And there's plenty of good detail about quasi still lifes... let's throw caution to the winds (um, so to speak) -- but not complicate things by linking from the other still-life definitions in a quasi-ward direction, though there will be links the other way:

:quasi still life: A {stable} {constellation} where the individual {still life}s share dead cells, so the neighborhoods of those dead cells are changed, but all cells that used to remain dead from under-population still do so. Under Life rules, this occurs when objects are diagonally adjacent (e.g., two {block}s sharing a single diagonal neighbor) or when single protruding cells in two objects such as {tub}s share multiple neighbors. The term is due to Mark Niemiec.
----------------
Bits Count
---- --------
8 6
9 13
10 57
11 141
12 465
13 1224
14 3956
15 11599
16 36538
17 107415
18 327250
19 972040
20 2957488
21 8879327
22 26943317
----------------
As the number of bits increases, the quasi still life count goes up exponentially, by slightly more than a factor of three -- approximately O(3.04^n). By comparison, the rate for {strict still life}s is about O(2.46^n) while for {pseudo still life}s it's around O(2.56^n).
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Re: Life Lexicon update

Postby Apple Bottom » September 1st, 2017, 3:01 pm

dvgrn wrote:-- Well, here we are adding to the number of usage instances every time we bring the darn things up. And there's plenty of good detail about quasi still lifes... let's throw caution to the winds (um, so to speak) -- but not complicate things by linking from the other still-life definitions in a quasi-ward direction, though there will be links the other way:


Excellent definition! I'm always for throwing caution to the winds, too -- and what good is being the editor if you can't occasionally sneak things past the editor... ;)
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Re: Life Lexicon update

Postby Apple Bottom » September 1st, 2017, 7:32 pm

Apologies for double-posting, and for straying off-topic again as well--

I've added a section on quasi still lifes to the still life article on the LifeWiki, reworked the table and included quasi still life counts, and done a few other edits for clarity/correctness/completeness.

I noticed that the quasi still life counts don't have an OEIS sequence, BTW, so if anyone wants to submit them, that would be great. (Once it's approved I'll make a template for it on the LifeWiki as well, like Template:A019473 etc.)

Speaking of the OEIS, A019473 is currently called "Number of stable n-celled patterns ("still lifes") in Conway's game of Life", which is misleading; it really should be called "Number of inseparable stabled n-celled patterns ("strict still lifes") in Conway's Game of Life" or so. A056613 also doesn't give a definition of pseudo still life, so maybe that could get one.
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Re: Life Lexicon update

Postby dvgrn » September 5th, 2017, 11:09 pm


Okay, the HTML files in question are temporarily back for their first post-Golly-3.0 review. The two-week countdown clock got reset by several errors that were pointed out via email this morning. So now it's up to someone else to find a typo or factual error, or suggest a specific definition that really couldn't possibly be left out of Release 26.

There have been a few more rounds of offline emails since Golly came out, mostly from David Bell, and so there are several more new definitions and alterations. Here are (most of) the things that changed recently and could probably stand to be double-checked... but as recent experience proves, other definitions could still be wrong, too!

:banana spark:
:burn:
:catalyst:
:colour-changing:
:colour-preserving:
cordership:
:figure-8:
:Garden of Eden:
:glider synthesis:
:GIG:
:grandparent:
:lifesrc:
:mc:
:macrocell:
:NW31:
:NW31T120:
:parent:
:pseudo still life:
:quad pseudo:
:quasi still life:
:reflector:
:rle:
:still life:
:strict still life:
:transparent debris effect:
:triple pseudo:
:tic tac toe:
:tubstretcher:
:wire:
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Re: Life Lexicon update

Postby Apple Bottom » September 6th, 2017, 5:57 am

dvgrn wrote::NW31:
:NW31T120:


Neat, I like how there's an explanation included for the naming scheme for this kind of pattern. That's something the LifeWiki could also use: an explanation of why things like converters, Herschel conduits etc. are called what they are called.

dvgrn wrote::stable reflector:


This doesn't seem to exist.

dvgrn wrote::still life:


Typo: "In rare cases bove a certain size threshold [...]" Also, a still life that can be divided into two or more stable components can be either a :pseudo still life: or a :quasi still life:.

Another question: I noticed that Simon Ekström's last name is consistently spelled "Ekstrom". Is this intentional?
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Re: Life Lexicon update

Postby dvgrn » September 6th, 2017, 9:09 am

Apple Bottom wrote:Another question: I noticed that Simon Ekström's last name is consistently spelled "Ekstrom". Is this intentional?

Yes. It was supposed to be only temporary, but the change slipped through into the final version when I ran short of time. Some issues came up in the very first processing stage, with my Python word-wrapping script complaining about the "ö" character in the source ASCII:

Python error:
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "word-wrap.py", line 1945
SyntaxError: Non-ASCII character '\xc3' in file word-wrap.py on line 1946, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details

I was worried that later conversion stages would have similar problems, since I don't think accented characters had appeared in the Lexicon before. Didn't want some browser or other to display "Ekstr&ouml;m" or some such, because of some subtlety I hadn't heard about.

However, it really looks like the Python stage is the only one that has any problem with \xc3 characters, and all that needs is a # coding=latin-1 line at the top, so I probably should have left the ö's in. I've restored them in the published online draft. If anyone with any OS/browser combination sees a problem with the ö's, please let me know! Samples are in :c/10 spaceship:, :copperhead:, :fireship:, :single-channel:, :Snark:, and :strict still life:.

EDIT: Arrgh, no, my paranoia was justified: Stephen Silver's conversion code didn't plan for ö's, so it produces "Ekström" instead of "Ekström" in its text output -- and, just to add insult to injury, "Simon Ekströ<i>m</i>" in the HTML. I think I've successfully repaired everything, but please do let me know if any trouble shows up.

Apple Bottom wrote:
dvgrn wrote::stable reflector:

doesn't seem to exist.

Oops, right, it's just under "reflector" -- I forget what minor thing I had to change, and when, but apparently I can't be trusted to notice my own typos any more so it's worth having more eyes on it.

Apple Bottom wrote:Also, a still life that can be divided into two or more stable components can be either a :pseudo still life: or a :quasi still life:.

Or a :constellation:, but unfortunately the terms aren't mutually exclusive -- quasi still lifes are also constellations, but constellations obviously aren't necessarily quasi still lifes. Have updated the :still life: definition accordingly. So much for sneaking in :quasi still life: without advertising it...!
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Re: Life Lexicon update

Postby Apple Bottom » September 6th, 2017, 9:28 am

dvgrn wrote:EDIT: Arrgh, no, my paranoia was justified: Stephen Silver's conversion code didn't plan for ö's, so it produces "Ekström" instead of "Ekström" in its text output -- and, just to add insult to injury, "Simon Ekströ<i>m</i>" in the HTML. I think I've successfully repaired everything, but please do let me know if any trouble shows up.


Everything looks fine to me now.

Apple Bottom wrote:Also, a still life that can be divided into two or more stable components can be either a :pseudo still life: or a :quasi still life:.

Or a :constellation:, but unfortunately the terms aren't mutually exclusive -- quasi still lifes are also constellations, but constellations obviously aren't necessarily quasi still lifes. Have updated the :still life: definition accordingly. So much for sneaking in :quasi still life: without advertising it...![/quote]

There's two entries for "still life" now, with the first including just the opening paragraph, and the second having the full entry. ;)

Ah, and quasi still lifes are constellations? I was actually under the assumption that for a "proper" constellation, the zones of influence of the constituent parts shouldn't overlap.

OTOH, they clearly overlap in, say, the traffic light. Is that considered a constellation? The LifeWiki only called it a "formation" until earlier this year, when User:AwesoMan3000 edited it to call it a constellation, and he's clearly not an expert.

Of course, neither am I, and my understanding of the intricacies of all these pattern categories has, well, room for improvement.
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Re: Life Lexicon update

Postby dvgrn » September 6th, 2017, 10:50 am

Apple Bottom wrote:There's two entries for "still life" now, with the first including just the opening paragraph, and the second having the full entry. ;)

D'oh! Will patch eventually. Grumble, grumble. Meanwhile use the multipage or ASCII versions.

With this o-umlaut detail I'm back to having way too many things that the automated conversion system doesn't cover. Next step is to write a probably-Python script to post-process the output from htmlize.exe. This is a terrible idea, of course, but not as terrible as continuing to apply the various patches manually.

Most likely the whole automated conversion will move to Python eventually, just because I'll probably create fewer mysteriously annoying bugs rewriting the whole thing, as opposed to trying to get the C code to do everything I want it to do.

Apple Bottom wrote:Ah, and quasi still lifes are constellations? I was actually under the assumption that for a "proper" constellation, the zones of influence of the constituent parts shouldn't overlap.

OTOH, they clearly overlap in, say, the traffic light. Is that considered a constellation?

I'm not an expert either, but yes, there seems to be a consensus here that includes the originator of the term. If the definition gets into the Lexicon with that specific point clearly addressed, I figure that should cut down on the pointless arguments about it...!

Notice that, per the above link, no one should complain even if something like a bi-block or a triple/quad pseudo is referred to as a constellation. It's a constellation of two blocks (that happen to be combined into a pseudo still life).

I'm somewhat annoyed that the definition of "constellation" specifically mentions "two or more". It would be easier if it was just "one or more", in which case every still life would be a constellation and you wouldn't have to worry about picking apart pseudo still lifes (especially the triple and quad variety). But that's probably just me being lazy, and wanting to be able to say just "constellation" instead of "still life or constellation" when I'm talking about, say, intermediate targets in a slow salvo construction.

-- Yes, "still life or constellation" really means "strict or pseudo still life or constellation", and also I could just say "still life" because that technically includes constellations. However, I think "still life" is clear as a shortcut for "one stable object of some kind" -- but it doesn't clearly invoke the idea of "could be more than one" even though that's true. So "still life or constellation" is probably worth saying, to be clear instead of just technically correct.
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Re: Life Lexicon update

Postby Apple Bottom » September 6th, 2017, 12:10 pm

dvgrn wrote:I'm not an expert either, but yes, there seems to be a consensus here that includes the originator of the term. If the definition gets into the Lexicon with that specific point clearly addressed, I figure that should cut down on the pointless arguments about it...!

Notice that, per the above link, no one should complain even if something like a bi-block or a triple/quad pseudo is referred to as a constellation. It's a constellation of two blocks (that happen to be combined into a pseudo still life).


I must admit I'm not entirely convinced, in light of what Mark wrote there--

mniemiec wrote:A pattern's connectivity (e.g. strict object, pseudo-object, quasi-object, or constellation) is independent of its periodicity (e.g. stable, oscillating, or unstable).

Stable patterns can be still-lifes (e.g. block), pseudo-still-lifes (e.g. two adjacent blocks), quasi-still-lifes (two adjacent tubs), or still constellations (e.g. blockade).


This sounds to me like "strict object", pseudo-object", quasi-object" and "constellation" are all mutually exclusive (and that they furthermore exhaust all possible options), and that this remains true if you replace "objects" with "still lifes".

This is underlined further down, where he writes:

mniemiec wrote:Stationary oscillating patterns can be oscillators (e.g. blinker), pseudo-oscillators (e.g. block on beacon), quasi-oscillators (e.g. traffic light), or oscillating constellations (bookend ash).


...so using Mark's terminology at least (which is probably as authoritative as it gets), traffic lights are NOT, in fact, constellations, but rather a "formation" of oscillators, to use the LifeWiki's term (and a "pattern", of course, but that goes without saying).

Mark also replies to Calcyman's assertion (that quasi-objects are to be considered constellations) saying that "
Under existing definitions, that do not distinguish quasi-objects,
this is true" (emphasis mine) -- which I would understand to mean that under newer/better/more accurate definitions, it is not true.

I just noticed again that he also recommended referring to "stable clusters" rather than "stable objects" in my ASCII flowchart; looks like I'll have to update the Dia-drawn version on the wiki.

Side note (for my own reference, mostly): "object" then seems to be generic term generalizing "still life", "oscillator" etc., allowing for subdivision into strict, pseudo-, quasi- and constellations. A "constellation" is made up of several "clusters", and "formation" is either equivalent to "cluster", or a more general term referring to any arrangement, cluster OR constellation.

(Do you ever feel like you're drowning in terminology?)

dvgrn wrote:I'm somewhat annoyed that the definition of "constellation" specifically mentions "two or more". It would be easier if it was just "one or more", in which case every still life would be a constellation and you wouldn't have to worry about picking apart pseudo still lifes (especially the triple and quad variety). But that's probably just me being lazy, and wanting to be able to say just "constellation" instead of "still life or constellation" when I'm talking about, say, intermediate targets in a slow salvo construction.

-- Yes, "still life or constellation" really means "strict or pseudo still life or constellation", and also I could just say "still life" because that technically includes constellations. However, I think "still life" is clear as a shortcut for "one stable object of some kind" -- but it doesn't clearly invoke the idea of "could be more than one" even though that's true. So "still life or constellation" is probably worth saying, to be clear instead of just technically correct.


Maybe just "stable pattern", or "stable subpattern", "stable component", or something along those lines?
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Re: Life Lexicon update

Postby dvgrn » September 6th, 2017, 1:27 pm

Apple Bottom wrote:I must admit I'm not entirely convinced, in light of what Mark wrote there...

... using Mark's terminology at least (which is probably as authoritative as it gets), traffic lights are NOT, in fact, constellations, but rather a "formation" of oscillators, to use the LifeWiki's term (and a "pattern", of course, but that goes without saying).

Mark also replies to Calcyman's assertion (that quasi-objects are to be considered constellations) saying that "
Under existing definitions, that do not distinguish quasi-objects,
this is true" (emphasis mine) -- which I would understand to mean that under newer/better/more accurate definitions, it is not true.

Hmm. It seems to me you might be getting a little too theoretical there, with your hypothetical newer/better/more accurate definitions.

I'd say the Lexicon should not even try to limit itself to the one best possible definition of every term. Its job is to document common usage, not to be a mathematically perfect textbook.

So here's my chain of crackpot logic:

Consider, say, two blocks sharing a diagonal neighbor cell.

It's much more common usage to label those two blocks as a "constellation", than to say "no they're not, they're a single quasi still life!" Most people probably don't even know what quasi still lifes are -- those only made it into the Lexicon because we had some nice statistics about them! -- so that second option can't be common usage yet.

Therefore the Lexicon definition of "constellation" has to be allowed to overlap with "quasi still life".

Otherwise we'd be trying to legislate a significant restriction to the term "constellation". And since the restriction would be for what looks like boring technical reasons, quite justifiably nobody will pay any attention -- everyone will keep using "constellation" to mean things like those two blocks, whenever they darn well please. And then the Lexicon will have to say annoying pedantic things like "many people use {constellation} when they're talking about {quasi still life}s".

Seems to me that's all just asking for trouble.

I don't think it even makes sense for the Lexicon to mention the possibility that "constellation" might be considered to exclude quasi still lifes. From a classification point of view, that use of "constellation" is certainly cleaner, but it's just plain not common usage at the moment. I figure if the concept turns out to be needed, someone will start referring to it as a "strict constellation" or whatever, and people will start using that, and maybe it will get into the 2030 edition of the Lexicon...!

One more quote from Mark 39453:12, while we're at it:

mniemiec wrote:(Originally, pseudo-objects were also considered constellations. In fact, apgsearch currently still treats them as such.)

This "original" usage seems like another reason why :constellation: should be documented as a simple all-inclusive term. If you can see that a pattern is made up of a bunch of blocks and beehives and blinkers and so forth, you can safely call it a constellation. Even if the pieces are kind of close together, you don't have to stop and look to see exactly how close they are.

Apple Bottom wrote:(Do you ever feel like you're drowning in terminology?)

Nah. Well, maybe a little, but as soon as the feeling starts I just say to myself, "Eh, who really cares?" -- and that floats me right back to the surface again.

EDIT: All of this is just my opinion, of course, and as the previous paragraph implies it's not a terribly strongly held opinion. Sufficient objections will certainly change my mind -- sufficient either in quality or in quantity, I don't need both... At the moment I'm thinking maybe the following adjustment would be good:

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 can referred to as a {constellation}. If its cells form a single {cluster} it is also, more specifically, either a {pseudo still life} or a {quasi still life}.

I think that makes a clear and consistent definition that aligns reasonably well with common usage. Alternative suggestions are welcome, especially if they include complete specific wording for any and all related definitions that would have to be changed, like for :constellation:...!
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Re: Life Lexicon update

Postby Sokwe » September 6th, 2017, 11:39 pm

  • {pre-pulsar}:
    By other means the replication of the pre-pulsar can be made to occur in just 14 generations as half of it is eaten; this allows the construction of p28 and p29 oscillators, and is in fact the only known method for creating a p29 oscillator.

    This is no longer true due to this discovery by Ivan Fomichev. Interestingly, the new oscillator does still use a pre-pulsar. It just doesn't use the 14-gen pre-pulsar push.
  • {2c/3 wire}
    There is a known 2c/3 wire elbow that is usable in some situations, but it has the drawback that it produces two output signals for each input signal, and so unfortunately can not be used to complete a loop.

    It doesn't really produce two output signals. It converts a single-length signal into a double-length signal. Also, it says "In 2017 Martin Grant observed that the 2c/3 signal can be split successfully into two half-signals", but this fact was known long before 2017. It is demonstrated in this p9 signal injector discovered by Dean Hickerson in the late 90s:
    x = 28, y = 29, rule = B3/S23
    obo3b2o$2obobo2bo$3bob2obo$3o2bo2bob2o$o2bo3b2obo$b2o8bo$7b4o$b2o3bo$b
    o2bo2b6o$3b2obo6bo$4bobo2b5o$2bobobobo7bo$2b2o2bobo2b6o$6bobobo$7b2obo
    2b6o$10bobo6bo$10bobo2b5o$11b2obo7bo$14bo2b6o$14bobo8bo$13b2obo2b7o$
    16bobo$16bobo2b5o$17b2obo4bo$20bo2bo$20bobob4o$19b2obo4bo$23b3o$25b2o!

    Maybe also add a "See also {5c/9 wire}."
  • {5c/9 wire}: maybe add "See also {2c/3 wire}."
  • {AK47 reaction}: last parenthetical sentence should include mention of AK94 gun.
  • {apgsearch} change "results" to "result".
  • {arm}: sometimes referred to as a "wing".
  • {B29}: Mention glider synthesis by Tanner Jacobi, 5 April 2015.
  • {barberpole}: See also {pseudo-barberpole}.
  • {pseudo-barberpole}: See also {barberpole}.
  • {breeder}: Last sentence should be "The known breeder with the smallest initial population is {switch-engine ping-pong}."
  • {omniperiodic}: should remove "further reduced by Noam Elkies between 1999 and 2002". There have been many reductions of the list by many people. It's probably overkill to list them all, but seems incomplete if we list just one.
  • {orphan}: second sentence should say "an orphan".
  • {OTCA metapixel}: "LWSS spaceships" should be changed to "LWSSs" or "LWSSes" or whatever the preferred plural is.
  • {overclocking}: The discussion of the Silver reflector seems to have a lot of redundancies. Maybe just remove the last two sentences of the first paragraph?
-Matthias Merzenich
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Re: Life Lexicon update

Postby dvgrn » September 7th, 2017, 10:42 pm

Sokwe wrote:
  • {pre-pulsar}
  • {2c/3 wire}
  • {5c/9 wire}
  • {AK47 reaction}
  • {arm}
  • {B29}
  • {barberpole}
  • {pseudo-barberpole}
  • {breeder}
  • {omniperiodic}
  • {orphan}
  • {OTCA metapixel}
  • {overclocking}...

Thanks! Have attempted to fix all of the above, hopefully without introducing any new errors. The new HTML can be found at the same links.

David Bell also emailed with a number of good suggestions, one of which was that the definition of :puffer: had only been updated as of 2006 and had already been getting to be a run-on then -- and now didn't list nearly all of the new puffer speeds (even if you didn't include puffers from self-constructing spaceships, which would make it hopeless to list them all.)

After some shuffling and adding and subtracting, I ended up with this text:

:puffer: An object that moves like a {spaceship}, except that it leaves debris behind. The first known puffers were found by Bill Gosper and travelled at c/2 orthogonally (see diagram below for the very first one, found in 1971).
.***......*.....*......***.
*..*.....***...***.....*..*
...*....**.*...*.**....*...
...*...................*...
...*..*.............*..*...
...*..**...........**..*...
..*...**...........**...*..
Not long afterwards c/12 diagonal puffers were found (see {switch engine}). Discounting {wickstretcher}s, which are not puffers in the conventional sense, no new velocity was obtained after this until David Bell found the first c/3 orthogonal puffer in April 1996. Other new puffer speeds followed over the next several years.
Many spaceships that travel orthogonally at a speed less than c/2 have useful side or back {spark}s. These can be used to perturb {standard spaceship}s that approach from behind. A common technique for creating puffers for a new speed uses a {convoy} of the new spaceships to create debris from an approaching standard spaceship such that a new standard spaceship is recreated on the same path as the original one. This forms a closed loop, resulting in a high-period puffer for the new speed.
As of this writing (August 2017) puffers have been found matching every known velocity of {elementary} spaceship, except for c/6 and c/7 diagonal.

Did I make things better, or no?

Other definitions that were adjusted based on David Bell's suggestions -- including definitions that I noticed I hadn't finished properly while looking at those suggestions -- include

:phoenix:
:fireship:
:tumbler:
:slow elbow:
:lossless elbow:
:single-channel:

Y'all please have another look if you can -- the two-week timer has started ticking down again...
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Re: Life Lexicon update

Postby Sokwe » September 8th, 2017, 5:42 am

dvgrn wrote:Did I make things better, or no?

It looks good to me.

{syringe}: I think it should say "welded still life" or "welded catalyst" or something along those lines.
-Matthias Merzenich
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Re: Life Lexicon update

Postby Sokwe » September 9th, 2017, 5:42 am

What truly is a "quetzal"? The lexicon doesn't give a direct definition, but it does imply the one given on the wiki:
A Quetzal is a Herschel track-based gun with a period lower than 62.

That raises the question: what counts as Herschel track-based? The original p59 gun used Herschel tracks only for glider reflection. Now that we have the snark, we have essentially the same gun without any reliance on Herschel tracks.

The p58 and p61 guns use Herschel tracks to make glider duplicators, so they're closer to the original quetzals. The glider-duplication technique could also be used at p59, so we could still have a p59 quetzal even if the first gun doesn't count. The p57 gun is a traditional quetzal. It just uses a p3 oscillator to liberate a glider from the p57 Herschel loop.
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Re: Life Lexicon update

Postby calcyman » September 9th, 2017, 6:02 am

Sokwe wrote:
A Quetzal is a Herschel track-based gun with a period lower than 62.

That raises the question: what counts as Herschel track-based? The original p59 gun used Herschel tracks only for glider reflection. Now that we have the snark, we have essentially the same gun without any reliance on Herschel tracks.


It's still a Quetzal: https://en.wikipedia.org/wiki/Ship_of_Theseus
What do you do with ill crystallographers? Take them to the mono-clinic!
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Re: Life Lexicon update

Postby dvgrn » September 20th, 2017, 8:37 am

People have sent enough updates and corrections since Golly 3.0 came out, that it probably makes sense to bump the version number to Release 27 -- especially since that allows the release date to fall on International Talk Like a Pirate Day, just like version 25r last year.

Out of laziness, I've just replaced the new files in the /release26 folder, but I think I've updated all the actual version numbers and dates:


So the clock is ticking down again: what have I made a mess of, in the new material that's been added? Since the last post above on September 5th, if my records are right, I've added or changed

:2c/3 wire:
:almost knightship:
:asynchronous:
:beehive stopper:
:clock:
:elementary conduit:
:F171:
:glider pair:
:glider stopper:
:Herschel stopper:
:knightship:
:Orthogonoid:
:partial result:
:pentadecathlon:
:pufferfish spaceship:
:search program:
:singleton:
:SW-2:
:SW-2T21:
:synchronous:
:technology:
:toad:
:tremi-Snark:
:turtle:

That may not be quite a complete list, but it's pretty close. Last call (again) for corrections! With any luck this will go live at conwaylife.com/ref/lexicon in the next week or two.

EDIT: Found five mistakes so far, which I'll patch tonight:
:glider stopper: 199? -> 1996
:Orthogonoid: n -> no
:partial result: substitutional -> substantial
:search program: Garden of Edens -> Gardens of Eden
:tremi-Snark: a -> A

EDIT2: David Bell found another typo and contributed a few more changes to :stamp collection: and :eater1:, and I added a pile of {spaceship} links in the new entries I had written for Release 26, as I think Sokwe suggested a while back. Have uploaded all the corrections. I might be done now -- here's hoping!
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