Tag Archives: video

Deterministic vs random, an example of grandiose shows vs quieter, functioning anarchy

In the following video you can see the deterministic, at the right random evolution of the same molecule, duplex.mol from the chemlambda repository. They take about the same time.

The deterministic one is like a ballet, it has a comprehensible development, it has rhythm and drama. Clear steps and synchronization.

The random one is more fluid, less symmetric, more mysterious.

What do you prefer, a grand synchronized show or a functioning, quieter anarchy?

Which one do you think is more resilient?

What is happening here?

The molecule is inspired from lambda calculus. The computation which is encoded is the following. Consider the lambda term for the identity function, i.e. I=Lx.x. It has the property that IA reduces to A for any term A. In the molecule it appears as a red trivalent node with two ports connected, so it looks like a dangling red globe. Now, use a tree of fanouts to multiply (replicate) this identity 8 times, then build the term

(((II)(II))((II)(II)))(((II)(II))((II)(II)))

Then use one more fanout to replicate this term into two copies and reduce all. You’ll get two I terms, eventually.
In the deterministic version the following happens.

– the I term (seen as a red dangling node) is replicated (by sequence of two rewrites, detail) and gradually the tree of fanouts is destroyed

– simultaneously, the tree of applications (i.e. the syntactic tree of the term, but seen with the I’s as leaves) replicates by the fanout from the end

– because the reduction is deterministic, we’ll get 16 copies of I’s exactly when we’ll get two copies of the application tree, so in the next step there will be a further replication of the 16 I’s into 32 and then there will be two, disconnected, copies of the molecule which represents ((II)(II))((II)(II))

– after that, this term-molecule reduces to (II)(II), then to II, then to I, but recall that there are two copies, therefore you see this twice.

In the random version everything mixes. Anarchy. Some replications of the I’s reach the tree of applications before it has finished to replicate itself, then reductions of the kind II –> I happen in the same time with replications of other pieces. And so on.
There is no separation of stages of this computation.
And it still works!

I used quiner_experia, with the mol file duplex.mol. The first time I modified all the weights to 0 (to have deterministic application) and took the rise parameter=0 (this is specific to quiner_experia, not present in quiner) too, because the rise parameter lower the probabilities of new rewrites, exponentially, during the same step, in order to give fair chances to any subset of all possible rewrites possible.
Then I made a screencast of the result, without speeding it, and by using safari to run the result.
For the random version I took all the weights equal to 1 and the rise parameter equal to 8 (empirically, this gives the most smooth evolution, for a generic molecule from the list of examples). Ran the result with safari and screencasted it.
Then I put the two movies one near the other (deterministic at left, random at right) and made a screencast of them running in parallel. (Almost, there is about 1/2 second difference because I started the deterministic one first, by hand).
That’s it, enjoy!
For chemlambda look at the trailer from the collections of videos I have here on vimeo.

Advertisements

Another chemlambda reduction and a weird Google bug

 

This is the end of the computation of the monus function monus(a,b)=a-b if a>=b, else 0, for a=3 and b=20.

It is the last part of the computation, as recorded at 8X speed from my screen.

If you want to see all of it then go to https://github.com/chorasimilarity/chemlambda-gui/tree/gh-pages/dynamic , clone it and then type: bash moving_alt.sh and choose monus.mol from the list of mol files.

It is used the deterministic algorithm, this time, which makes all possible moves every time.

What is interesting about this computation is the quantity of trash it produces.

Indeed, I took a lambda term for the monus, applied it to 3 and 20 (in Church encoding), then applied it to successor then applied it to 0.

In the video you see that after the result (the small molecule connected to the blue dot, it i sthe chemlambda version of 0 in the Church encoding), there is still a lot of activity of destroying the rest of the molecule. It looks nice though.

Something strange happened when I tried to publish the video (there are so many strange things related to the dissemination of chemlambda that they become a family joke, some of the readers of this blog are aware of some of those).

After I completed the description I got the warning shown in the following video:  “Brackets aren’t allowed in your description”

 

For example this previous video has brackets in the description and in the title as well

and all worked well.

Anyway I eliminated the brackets but the warning remained, so eventually I got out from my google account and done something else.

Sometimes later I tried again, experience described in this video (which took a LOT of time to be processed)

At the beginning the fields for title and description were void and no error was announced.

After I filled them happened what you see in the video.

I understand that Google uses a distributed system (which probably needs lots of syncs, because you know, that is how intelligent people design programs today), but:

  • the “brackets are not allowed” is bogus, because a previous video worked perfect with brackets in the description,
  • the “unknown error” means simply that there was some trace left on my computer that there was an imaginary error in the previous try, so instead of checking if there is an error this time, I suppose that the browser was instructed to read from the ton of extremely useful cookies google puts in the user’s place.

_________________________________________________________________