"There's a mirage when you first look at it, like with a lake. What you see is just the surface of the lake, and that's a two dimensional view. But when you put your hand in, you find that there's depth to it. It's not just one dimension or two, but a three dimensional design." -- Carl Sassenrath on Rebol, 1996 (https://web.archive.org/web/20000830133509fw_/http://www.lin...)
> Wait, you're writing about "3-dimensional source code" and the dimensions aren't settled yet? That just makes me glad I didn't read your slides, and even less likely to put in the effort next time. I'll repeat my earlier comment: your MVPs are too M and insufficiently V.
> How are you so sure that you won't settle on 2 or 4 dimensions? (Let us stipulate that 5 is right out.)
Sorry, the language itself is fully settled, the only question is with our hardware prototypes, we've found a way to compute with the ETN programs mapped to 2-dimensions, and a machine structure where we can compute answers with a source program mapped to 3-dimensions. But really both are 3-dimensional, the former it's just the Z-axis doesn't vary.
In the 3-D version, the first word of a node (aka the head/base/instruction/type/command), is at z 1, and subsequent words go up the z-stack. In the 2-d version, subsequent words just go up the x-dimension. They actually both offer advantages, and we'll figure out which is better I'm sure in the next year or so.
Again, this stuff is at the cutting edge of the hardware research. We're talking about a whole new type of machine architecture without registers.
> You'll need to show me these empirical studies.
Totally agree. We will.
> I haven't actually ever heard a story that accounts for 99% of bugs. Pretty much every software engineering study ends up with a much flatter profile than that. You have to do many things right to eradicate 99% of bugs.
Agreed. And to hit that 99%, we're going to need the new hardware, so that is quite far off (3 - 20 years, hard to predict). But we can hit 90% fewer with ETN software alone.
> From what I can tell, ETNs are mostly about eliminating punctuation and replacing it with indentation. Is that right?
No. Forget about the punctuation of newlines and spaces. Think about it as Cartesian coordinates. ETNs are about giving source code physical dimensions. About making sure that source code could directly be built out of circuitry. Think of ETN programs like something you could build in a Voxel editor like MagicaVoxel. Each block holds a word, which is just a number from 0 to infinity, and problems are trees of these numbers connected in physical space. Sorry if that's not clear. I think the more code and tools we build the easier it will be to understand.
> Is upgrading the syntax to ETNs all that's needed to eliminate 99% of bugs?
No. To reduce bugs by 90% (99% won't be possible until we have ETN machines) you also need well designed ETNs. Which have good FPL things like no side effects, prefix notation, DRY, good naming, good interfaces, et cetera. Great question. Working on a release shortly with a lot more tools and help on building great ETNs.
> Nail down the input space, and bugs go down because your tests fail more often.
I like that! I'm a big fan of strongly typed languages and the idea they basically prove your program correct at compile time if you think more about your types.
Thanks for the feedback! I hope the next wave of ETN stuff will help start to demonstrate the benefits better.
Wait, you're writing about "3-dimensional source code" and the dimensions aren't settled yet? That just makes me glad I didn't read your slides, and even less likely to put in the effort next time. I'll repeat my earlier comment: your MVPs are too M and insufficiently V.
How are you so sure that you won't settle on 2 or 4 dimensions? (Let us stipulate that 5 is right out.)
> empirically 99%+ of bugs occur in extraneous parts of the code
You'll need to show me these empirical studies.
I haven't actually ever heard a story that accounts for 99% of bugs. Pretty much every software engineering study ends up with a much flatter profile than that. You have to do many things right to eradicate 99% of bugs.
> ETNs start bringing us closer to the absolute minimum, perfect program necessary to solve a problem.
From what I can tell, ETNs are mostly about eliminating punctuation and replacing it with indentation. Is that right? If so, is your claim that "99% of bugs" are hiding in the punctuation?
Is upgrading the syntax to ETNs all that's needed to eliminate 99% of bugs? What about DRY? The value of good interfaces? Parnas's theory of information hiding? SOLID?
I'll trade my pulled-out-of-my-ass theory for yours. I think bugs arise because our representation of algorithms ("code") over-emphasizes the rules the algorithms performs, and under-emphasizes the input space that the rules are meant to operate on. Bugs arise when people modifying the code forget about rare areas of the input space, and the scaffolding around the project is unable to remind them. Nail down the input space, and bugs go down because your tests fail more often. You won't fix this problem no matter how much you tweak the superficial syntax with which you write code. (I work on this, so it was not pulled out of my ass just now: http://akkartik.name/about; https://github.com/akkartik/mu)
First, just want to say thank you so much, zck, for taking the time to write this feedback. It is so helpful and very much appreciated!
> Can you explain what the axes are, again? The Y axis is the line; that's pretty clear. But it seems like both the X axis and the Z axis are related to how many characters into the line one goes. (Edit: I just listened to the FAQ, and the Z axis is level of indentation. So for each Y axis, there's only one possible Z value, for any number of X values? That is, you can't have both (42, 27, 3) and (42, 27, 4). Is that right?)
Sorry, this is still slightly up in the air. The Y axis is equivalent to line number (this is fixed). The X axis is equivalent to indent level (this is fixed). Still running some hardware experiments to determine whether to use the Z axis for the words and model these programs as 3-dimensional or whether to stick to just the X axis and save the Z dimension for lines connecting assignment words with their references. I realize that's still not clear and I hope to add something on hover to Ohayo soon, so you can hover over a word and see the X,Y,Z location.
> On ohayo.computer, you might want to make it obvious that you have to open the developer console to see the output from running the code. This is the last thing I would think to do. Compare it to many other "run code online" sites, e.g. https://repl.it/JtNz/0, where there's both a "run" button so I don't have to hunt for hidden menus that explain what command to press, and a box in which output goes.
> On a technical note, Ohayo's fib.fire seems to be broken for me. Every box seems to have "no block 'X' found" in it: http://imgur.com/a/fwM8X. This happens in both firefox and chrome.
I'm sorry! I'm still figuring out best practices for designing ETNs, and I've been changed the instruction words a lot. I'm currently building a suite of utilities that will easily migrate programs from and older ETN version (in this case, Fire), to a newer version. This is definitely a critical need before this thing is ready for people to depend on, and I'm sorry about the trouble now. We have made a lot of progress in figuring out some best practices for ETNs (largely by stealing the best ideas from Haskell), and one of the next big changes will be a highly improved version of Fire that implements those best practices. But even when we have a much better and more stable version of Fire, I expect there will always be room for improvement, so will get some better systems in place to ensure people don't have to worry about breaking changes. Really sorry about that. I should add more disclaimers.
> This presentation doesn't seem to answer many of the questions I have about 3D Languages. Why are they better?
I hope the new console (which allows you to run/compile just a branch or single line of your program) starts to provide some hints as to how different ETNs are, and how they enable lots of beneficial things not possible in 1-dimensional languages and 1-dimensional terminals.
> You say you expect them to have fewer bugs, but I don't see why.
Much more to come on this. Basically the thrust is that empirically 99%+ of bugs occur in extanenous parts of the code. ETNs start bringing us closer to the absolute minimum, perfect program necessary to solve a problem. We will see a huge reduction in bugs just from going to ETNs => current high level languages => machine code, however, that's just the beginning. We're inventing a completely new non-von neumann architecture, 3-d machine architecture, that can compute high level ETN programs directly. But realistically that is years away from reliability. In the short term we'll be able to realize a lot of gains in bug reduction just from using ETNs that compile to 1D languages.
> You say that they're easier to understand, but even you have a problem figuring out what the location of a given character is!
I know, very embarrassing! That one is because the Z/X axis debate is still up in the air. Hopefully the correct answer in the design decision will emerge soon.
> I want to know why you think something, not just that you think something.
A lot of it is empirical. But it's the type of thing where I can see that ETNs will be 10-100x faster because they solve a lot of unsolved problems or poorly solved programming problems, but they won't be 100x faster until all the other stuff is there too (stuff like the code editor, which we finally just added). At this point I see no deal breakers and am highly confident all the predictions will come true (and then some), but it's a matter of still doing lots of grunt work to eliminate the trivial (but impactful) road blocks. But yeah, I fully agree with your sentiment and hope we can start to provide more hard data and direct proof about why we think these things.
> And, not to nitpick, but I really don't get the whole "ETN" phrase
This is a great nit! "Extended Tree Notation" is probably better. Thanks!
> So responding to your forum comment above and this, I would love for Try Arc to run purely client-side on a static site host like GitHub Pages. Unfortunately, as you mention here, it runs on a VPS (Linode) instead. The reason is that it's not all client-side - it actually communicates with an system arc3.1 hosted on the server.
Yes, I recall our email thread and I saw your email on there today, which I'm copying here in case other people are interested:
> I'm curious: how do you run things on your Linode? For example, I can't find the top-level html page in the repo. It seems like the repo runs inside an iframe of the "REPL" tab? Could you provide some instructions and peripheral config files (Apache/Nginx, etc.) to help make it turn-key? I don't want to make it onerous, but I think just a couple of lines and copy-paste will go a long way.
So responding to your forum comment above and this, I would love for Try Arc to run purely client-side on a static site host like GitHub Pages. Unfortunately, as you mention here, it runs on a VPS (Linode) instead. The reason is that it's not all client-side - it actually communicates with an system arc3.1 hosted on the server.
As for making the repo public, I think that is the logical (almost) next step. The only thing preventing me from doing that right now is a security concern. Try Arc isn't the only project I have hosted on that VPS. Currently there's a measure of "security through obscurity" that helps protect the other stuff on that server. I think the next step is to move it to a server where it's the only thing running. Then as soon as that's done I'll make the repo public.
I'll respond about the iframe and other configuration a bit later.
Strange, I had just restarted it early in the day. (And that's what I had to do just now.) It used to stay on for weeks or months on average before konking out. Perhaps it was a fluke today but we'll see if there's something that's repeatedly interfering with it being allowed to run.
Hi Evan! This thread reminds me that we had an email discussion back in 2014 about how tryarc is hosted, and whether we can provide separate sites for Arc 3.1 and Anarki. You even gave me access to the repo, but I never did anything with it :/
I'm looking at the repo now. I wonder if we could host it on Github pages. That would be the easiest and most future-proof approach. Lately I try to host new repos away from Github, but for now it may be best to have all these related projects in the github.com/arclanguage Org. Improved discoverability.
As a first step: how do you feel about making the repo public? ^_^
Can you explain what the axes are, again? The Y axis is the line; that's pretty clear. But it seems like both the X axis and the Z axis are related to how many characters into the line one goes. (Edit: I just listened to the FAQ, and the Z axis is level of indentation. So for each Y axis, there's only one possible Z value, for any number of X values? That is, you can't have both (42, 27, 3) and (42, 27, 4). Is that right?)
On ohayo.computer, you might want to make it obvious that you have to open the developer console to see the output from running the code. This is the last thing I would think to do. Compare it to many other "run code online" sites, e.g. https://repl.it/JtNz/0, where there's both a "run" button so I don't have to hunt for hidden menus that explain what command to press, and a box in which output goes.
On a technical note, Ohayo's fib.fire seems to be broken for me. Every box seems to have "no block 'X' found" in it: http://imgur.com/a/fwM8X. This happens in both firefox and chrome.
This presentation doesn't seem to answer many of the questions I have about 3D Languages. Why are they better? You say you expect them to have fewer bugs, but I don't see why. You say that they're easier to understand, but even you have a problem figuring out what the location of a given character is! I want to know why you think something, not just that you think something.
And, not to nitpick, but I really don't get the whole "ETN" phrase. It stands for "Extends Tree Notation", but then it's not even a noun, but an adjective! So something can't be an ETN, it can have the quality of ETN. You even seem to acknowledge this. At 7:35 in the video, you say "What fire is is a thing called an ETN. It extends tree notation." You should be able to replace "ETN" with "Extends Tree Notation", and have the sentence still make sense, like "I'm playing a CD" vs "I'm playing a Compact Disc". I'm harping on this because I think it's something I'm misunderstanding, but it seems to be near the core of your argument. Should ETN be a noun? Maybe it should be "Extended Tree Notation". And also, "ETN" seems to be identical to "indentation-based languages with weird syntax".
Arc's assignment operations are set up to acquire a global lock as they operate, achieved by use of an (atomic ...) block. This is so other threads can't observe the in-between states of operations like (swap ...) and (rotate ...). The documentation for 'atomic is here: https://arclanguage.github.io/ref/threading.html
Arc also has some support for continuations, which can serve as a kind of cooperative multithreading. Mainly, Arc just exposes 'ccc as a binding for Racket's 'call-with-current-continuation, and it uses Scheme's 'dynamic-wind to implement 'protect. These are documented here: https://arclanguage.github.io/ref/error.html
Those are features in support of concurrency, as in, the interleaving of multiple expression evaluations for the sake of avoiding verbose inversion-of-control coding styles. It looks like racket/place is particularly intended for parallelism, as in, the use of multiple processors at once for the sake of performance. I'd say Arc doesn't provide any particular support for parallelism yet, only concurrency.
The symptom was different (a copy/paste issue) but the phenomenon was the same (files with .arc extension not behaving normally). The cause is indeed that Emacs thinks .arc means an archive file. The solution is here:
The variable you need to change is auto-coding-alist, like this:
(push '("\\.arc$" . utf-8) auto-coding-alist)
The reason this problem was so confusing is that the settings in auto-coding-alist take precedence over some of the other things that seem like they ought to work but don't, like
modify-coding-system-alist (described above) or putting a character-encoding directive like:
-*- coding: utf-8 -*-
at the top of the file. Since it was surprisingly hard to track this down and I only found it on my dozen-th or so Google search, I'm making this comment verbose in the hope that the current thread will surface more easily in the future.
Cool. I look forward to reading some new stuff about it. I'll just comment on some of the things here.
> Version 1.2 (today) introduces the shortcut "shift+b" to build program, which will show you the compiled Js output for Fire programs. You can also use "command+shift+b" to build and save to file.
But for a run button, I'd think you want this to be as obvious as possible. So don't even bury it in a menu -- make a header with a giant "run" button. Or maybe not "giant", but somewhere that's displayed when you open the page.
> Another person emailed me and said it should start with "hello world", and not Fib. That's coming soon.
I feel like you want to have both. But yes, it's useful to have Hello World.
I do want to play around with this, so hopefully I can understand what it is soon.
I agree with every point you made and am working on fixing them.
> mainly seems to take as an axiom that tree-structured^1 languages are better.
Correct! And also correct that I haven't proven this to be the case yet. I'm heading in that direction and think by the end of week 1 of the announcement there should be more evidence in that regard. I just launched version 1.2 just now. In a Flow program, you can now add a ">3d" block, which can have a "content" property where you can add some ETN code and see it somewhat visualized in 3d. Rough version, but starting to hint at what's to come. Basically imagine a 100,000 line program, where you can visualize and manipulate the source (and AST!) in 3D, and it all runs blazing fast. That's where we are headed with this. I believe 2D/3D languages may be better because 1) it seems the constraints imposed by the criteria that source must map to physical dimensions helps avoid anti-patterns (but i don't have a proof yet on why) 2) our brains are wired to work in 3D. Although those are theoretical guesses. For me, 95% of why I believe they are better is because of my experience working with them the past few months (which I'm trying to bring that experience to others asap).
But yes. Agreed that I haven't proved this yet.
> I open http://ohayo.computer/, and the first thing presented to me is the Apple "The Crazy Ones" video. This is an extremely offputting message.
Haha, thanks for that feedback. Last week was a week with little sleep, and didn't have time to make a proper intro screencast, so put that up as a placeholder because I thought the "ones who see things differently" was apropos. That won't be up much longer. Thanks for sharing your thoughts.
> I'm seeing far more self-promotion than argument
Agreed. I just do believe in the potential impact of ETNs, and truly believe if anything I'm underselling the impact they could have, and if I got hit by a bus before I could provide more evidence I wanted to make sure people took notice and continued where I left off. Low bus factor last week--but now that is much higher! Maybe once more evidence is out there I can revisit all those posts and tone them down.
Another person emailed me and said it should start with "hello world", and not Fib. That's coming soon. Thanks for this additional feedback. Also, the Fire editing is brand new. It was very theoretical until last week. So the UX has a long way to go. I made some improvements this morning but still it's quite shitty. Working on it.
> How do I actually run any code?
Version 1.2 (today) introduces the shortcut "shift+b" to build program, which will show you the compiled Js output for Fire programs. You can also use "command+shift+b" to build and save to file.
> The File menu has no "run" option.
Great suggestion! Will likely add next version.
Also, another suggestion I got is to have a "Quick tips" that shows the top 5 things to do (like double click to add a node, ? for help, et cetera). Coming soon.
> source code that corresponds to what's shown
Shift+u. Again, great feedback. I'll add a File toggle and also a quick tip.
> I really just want to see how these things work. I don't want to see unsupported claims. I want to be able to write some code, or modify existing code. Please don't make it so hard for me to understand what this is.
Agreed! Thanks! I also made a lot of speed and test improvements this morning and will have project editing very soon.
>  I'm not trying to pick on the presentation for the sake of picking on it, but the pictures are extremely difficult to read, making it difficult to understand the argument. At least rotate the pictures so they're right-side-up. Scan them if you can, and do your best to write them with your best handwriting -- I have similarly bad handwriting, so I don't present people with handwritten documents if I can avoid it.
Haha, great points!
>  There appear to be multiple terms for this. It's somewhat confusing, because the picture proofs talk about "pure tree languages", but other things talk about ETNs (Extends Tree Notation), or "geometric trees". I don't think "pure tree language" in the picture means anything different from "tree" in the text, but I'm not sure of that. It would be useful to pick one name for each concept and stick to it.
Correct. I haven't found the correct mathematical term for it (I've searched graph, braid/knot, set, and some other theories). I bet there is one. If not, maybe I'll standardize on "Geometric Tree".
I'm having a pretty hard time understanding what this is, and I think a large part of this is that claims are stated instead of proven or explained. I see that the author thinks this is the future, but "what this is is self-evidently better" seems to be the argument most put forward, without being backed up by examples.
> In Lisp, which uses parantheses for structure and allows arbitrary whitespace, there are many ways to write your code, and not all of those ways arrange your source code into “geometric trees”. That is, if you connect the nodes of your program with lines, sometimes those lines will intersect or be coincident.
The presentation below^0 mainly seems to take as an axiom that tree-structured^1 languages are better. If you already believe tree-structured languages are better, then yes, Lisp is not as good.
But if you're not (yet) convinced? Ok, then that's just a property of languages that Lisp doesn't have. It also doesn't have the property that it requires semicolons at the end of the line, but by itself, that proof doesn't mean Lisp is worse than Lisp-with-semicolons-at-EOL. What about ETNs are better? Yes, if you draw lines from each node to its parent, they intersect -- but why do I care? Drawing lines like that is something I've never done. I assume your argument is something like "it's easier to understand code when it's clear", but I don't see you even state that argument, nevermind make a case for it.
So, being the non-academic that I am, I want to go to see how the code works. I open http://ohayo.computer/, and the first thing presented to me is the Apple "The Crazy Ones" video. This is an extremely offputting message. Between that and the article submitted here (Programming is Now Two-Dimensional), I'm seeing far more self-promotion than argument. It's like listening to a professional wrestler cut a promo: "Yeaaaaah brother. What 'chu gonna do, when tree languages run wild on you", but when it comes to that wrestler getting into the ring, the wrestler is nowhere to be found.
And that aside, I can't even seem to run any code! After reading the README, I learn that there are two languages -- Flow and Fire. I'm not a data science guy, so I click on `fib.fire`. I see this: http://imgur.com/a/3sIxf. There's no connection of anything at all, just a dozen random blocks of noise. How do I actually run any code? I don't see any "run" buttons. The File menu has no "run" option. How do I see this work? Also, I have no idea how this is connected to tree-structured languages! There are no lines between things, as seems to be the motivating factor of this paradigm!
Looking at the "sneak peek" video (http://breckyunits.com/ohayo-sneak-peak.html), apparently there is some sort of source code that corresponds to what's shown. But unlike in the video, I can't click to drag around things. I can't see the source code. Why not?
I really just want to see how these things work. I don't want to see unsupported claims. I want to be able to write some code, or modify existing code. Please don't make it so hard for me to understand what this is.
 I'm not trying to pick on the presentation for the sake of picking on it, but the pictures are extremely difficult to read, making it difficult to understand the argument. At least rotate the pictures so they're right-side-up. Scan them if you can, and do your best to write them with your best handwriting -- I have similarly bad handwriting, so I don't present people with handwritten documents if I can avoid it.
 There appear to be multiple terms for this. It's somewhat confusing, because the picture proofs talk about "pure tree languages", but other things talk about ETNs (Extends Tree Notation), or "geometric trees". I don't think "pure tree language" in the picture means anything different from "tree" in the text, but I'm not sure of that. It would be useful to pick one name for each concept and stick to it.
Wow, what a quote! That's exactly how I feel about Ohayo. That seems like a better approach--not to be in a big hurry to get people to use it today. Thank you akkartik. Really appreciate that advice!
My only concern pre-launch and announcement, was that I was going to get hit by a bus and the world would have to wait longer for someone else to stumble upon (and popularize) TN and ETNs. Now that it's out there and a few thousand people have seen it, I can take this more sensible approach.
Btw, just pushed version 1.1.0 if anyone's interested.
UX still needs work, but I rushed adding a "3D block" to the flow language, (using the vis.js library), so you can start to see what "3D" code looks like.
That motivation makes sense. Bear in mind, though, that the "less modest" approach has a limited amount of gas. It will stop working at some point.
I can relate with having these questions and considering the different strategies as well. If you really think that this is going to be your life's work, it's reasonable to burn some 'reputation' to get the word out. However, I've often been wrong before. Now I tend to err on the side of playing a long game.
Over time I've gained respect for the essential wisdom of this quote:
"We knew that Google was going to get better every single day as we worked on it, and we knew that sooner or later everyone was going to try it. So our feeling was that the later you tried it, the better it was for us because we’d make a better impression with better technology. So we were never in a big hurry to get you to use it today. Tomorrow would be better." -- Sergey Brin, as retold by Seth Godin in "The Dip"
Applicable to ideas like here just as much as products.
I totally agree. Although perhaps I wouldn't have gotten as much feedback had I taken a more modest approach? Hard to say. I still haven't done a good job communicating the benefits of ETNs yet, stemming from their 2D/geometric nature. Almost got version 1.1 of Ohayo done which makes another step toward that.
Thanks for the comments! The thing that z, readable, and wisp all lack, is that with ETNs every node has a point (x,y,z). So in addition to your source code mapping directly to your AST, it also maps to physical, geometric space (The Z axis is your program/document, the y axis is your line number, and the x axis is the column #/indent level).
So what you now have with ETNs, is the power of Lisp, now in a regular 2D/3D "structure", that you can inspect, visualize, and manipulate in new ways.
> 1. ETN uses fewer nodes. Why?
That's not compared to Lisps. Sorry, that was not clear. The paper was targeted toward a broader programming audience.
> 2. No parse errors. I have to say that I was writing in c++ recently, and the parsing wasn't an issue. And as you say, it doesn't make nonsense programs correct.
Ohayo briefly shows the power of no parse errors. Your program is parsed by little "micro-parsers", so there's no monolithic parse failure and programs can recover/autocorrect gracefully. More demonstrations here will do a better job of explaining. More to come.
> 3. No semantic diffs.
It's actually only "Semantic diffs" (not "not semantic diffs"). As opposed to syntax diffs. So "(+ 1 2)" and "(+ 1 2)" mean the same thing semantically in Clojure, for example, but git will give you a 1 line diff because of the whitespace syntax diff. In an ETN, "+ 1 2" and "+ 1 2" generally would be different, and could cause an ETN error unless the ETN allowed blank words.
4. Nothing collides. After years of going through every possible edge case, you cannot break TN. There is nothing that collides with the syntax. See for yourself. Download the library and create a TN with it's line/children set to something you think will collide. The indentation and ability to do "getTailWithChildren" takes care of all possible edge cases. (Sorry, I realize I still need to explain this better as this is a common concern and it is very surprising to people (myself included), that there are no edge cases that don't work.
Sorry, the lines in the geometric mapping of the source code are coincident. In drawing B) in the visual proof, the edges which connect the child nodes to their parents intersect and/or are coincident. So when you put Lisp source code onto graph paper, and draw boxes around the nodes, and line segments for edges, it shows why Lisp source is not a geometric language (I define a geometric language as one where there are no intersecting or coincident line segments).
Now, figure A) shows the same Lisp code, formatted differently, in a way that is a geometric language. But as you can see, that code is standard TN/ETN. Or perhaps another way to put it is ETNs are just Lisps with a whitespace syntax and no parentheses. Another reader on HN pointed me to I expressions (https://srfi.schemers.org/srfi-49/srfi-49.html), which I hadn't seen before and is 90% of the way there to TN and ETNs. The creator of I-Expressions have communicated briefly over email now and are going to be talking soon.
Anyway, perhaps another term for Tree Notation/ETNs is "Geometric Lisp", or "2-Dimensional Lisp". I'm not wedded to the terms TN/ETNs, although I do think it's better to have new terms, because I think these will come to dominate the usage of Lisp.
Still working on more updates and evidence on why I think these will be so big.
Though it's hard once again to understand. When are two nodes coincident? By definition you can only have one character in one place on the screen. Is he talking about indentation, that the same level of indentation can mean different things? That seems true of ETN as well, from what I can tell.
The pencil scratchings on the screenshots don't help either.
I thought all the emphasis of how great it was made it harder for people to understand _what_ "it" was. Probably a good idea to keep an initial post like this matter-of-fact. Motivate it with just one simple strength that's easiest to communicate. Describe the broader context and implications in a separate post, later, after people understand what it is.