TeX and the iPad
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Cheswick, William
TeX and other traditional text layout markup languages are predicated on the assumption that the final output format would be known to the nanometer. Extensive computation and clever algorithms let us optimize the presentation for a high standard of quality. But ebooks are here. The iPad has sold more than two million units in under three months, and, combined with other book readers, offers a new way to store and read documents. While these readers offer hope to newspapers (and perhaps doom to many physical bookstores), they are an increasing challenge to high quality text layout. Ebook users are accustomed to selecting text size (for aged eyes and varied reading conditions) and reader orientation. We can’t run TeX over a document every time a reader shifts position. Do we precompute and download layouts for various devices, orientations, and text sizes? Do we compromise our standards of quality to use HTML- and XML-based solutions? These are new challenges to the TeX community.
 And yes, I am using Keynote. I did try using Slitech for a little while and decided that it wasn't quite the same for me, then I give a lot of talks. So this has been working well. Hello. And so, okay, we'll give this a go. I'd like to thank you all for having a slot for me. I learned about this meeting about two weeks ago from Barbara. But there had been something on my mind I'd wanted to do along this field. So I said, ooh, I could give a paper on that. And I said, well, it's two weeks before the conference. There's no way they'll have a slot. And sent mails. I dashed off and titled and abstract and got back, sure, we'll fit you in. And even on the day you need to be fit in, because I can't stick around, unfortunately. So all I had to do was get a travel clearance, which arrived today. And by the time, between the time I submitted the travel clearance, I work at AT&T Labs, and the time my boss said, oh yeah, that's been approved, the price for the airfare had gone up 600 bucks. So I paid almost as much money as it costs to fly from Newark to Sydney to get here today, which means I don't like to do that. I'm a pretty cheap date, usually, but it means I'm flying first class out and back. I even bought one of those little power adapters for use in first class. The two legs out, the first one, the brand new first class seats didn't have any plugs for them. And for the second leg, it was broken. So I didn't get to do anything there. Anyway, United thanks you. There was no question about my flying first class, though I bought Coach. It was a $1,600 seat, which is not usual. Anyway, I'm only here for a day. And this is my first tech conference since, I think, 1988. My first real paper was at tech when I did the Pre-Muted Index for Tech some 25 years ago. I don't know if any of you use it. It's still there. You do use it? Not now. Well, so we'll get back to that in a moment. My problem was that I had learned tech and I'd just gotten learned tech. I started using tech. I don't know who knows it. Even Don seems a little sketchy on some of the commands. But I'd hack these things and I'd have epic battles where I just want to move this over one M. And you add spaces and it won't do it and so on. And I'd spent two days fiddling with this stuff. And my problem was that the answer to my question was the string command, but I didn't know how to ask the question or find where in the tech book it was. And that's what brought me to try to do a summary of every command in the whole thing, trying to use words that made sense so that if you sort of knew the right words, you might guide you to the right thing. And I submitted it and I guess it's still available. I don't know. It was generated on a Plan 9 operating system, which is long gone, but it could be easily resurrected if anyone cared. But what this really did was open my eyes to typography, that beautiful layout is important. Ligatures. Who knew? I'd been reading for 30 years and I didn't know f's were connected to i's. And I went back, wait a minute, can this be true? And would take some of my favorite books down and oh yeah, look at that. They're glued together. I never noticed that. But so it really gave me quite an appreciation and a huge amount of humility in terms of this is something you can try. It's like user interfaces. Everyone likes to try it, but not many are very good at it. And in fact, one of the reasons I have a Mac here. I also became a nitpicker. In my recent years, I review a lot of papers and my comments often slide into and by the way, this layout is crazy. Quote, don't use footnote in your books, Don. I put that in some of my reviews because a lot of people abuse them. And nowadays people are including fuzzy JPEG graphs. These are sometimes in visualization papers with three point font. And it's just awful. Anyway, so I became a nitpicker. I went on, this was just before I went off to Bell Labs where I learned how to be somewhat of an academic. And it served me well. I wrote a firewalls book with Steve Belevin in 1994, you folks may have heard of. We invented a style for the book but said, okay, Addison Wesley, have a shot at it. And Marty Rabinowitz was the typographer there and he told us how to fix things and we did that. But despite having done the second edition and published a number of papers, I haven't done much text since then until about two weeks ago when you folks said yes and suddenly I had to show something prototype. So I have been burning the midnight oil and telling my wife no, I don't have time to go for a walk. This program has to run by next Monday at 2 p.m. Pacific time. And I made it but it's a much better demo now than it was yesterday at this time. So I am an early adopter. My iPad arrived, I ordered it by mail. The UPS guy arrived on the day it first appeared. He was going around Somerset County, New Jersey handing these out to many people. And here you are, yeah, I got a lot more. And I started reading it and really realized that this changes everything. It's not a big iPhone, it's not a laptop, it's something new. It's a lovely way to read a book which means it changes the way you go to a bookstore, at least for me. When I go to a bookstore I'll buy junk books that I know I'm going to read once. But now that I have the iPad, some books I want to own and have a treasure and have people sign and so on and I'm going to reread them and give them to my kids. And others like today's latest take on cosmology. I'm not going to want to read that in 20 years. That's like an old textbook. I just don't need, I just want to read it once. And why would I buy some pulp when I could just put it into the iPad, which I don't want to forget, you know, just put it in here and now it's ready to read in some form or another. The typography in iBook and the Kindle app on the iPad are okay. I mean, you can read it, I've read about it a dozen books since late March. But they're not great. And I also thought, gosh, why would a book ever go out of print again? You just store it on disk. Well, heck, you know, the firewalls book, the first edition is still in print, even though the second edition came out in 2003. There are people who are still buying a book that talks about TIS's toolkit. You know, they're gone, it's decades gone, but they're still there and I thought, gee, I'm willing to charge them a buck 99 for the first edition. We could split it three ways between the publisher, the authors, and Apple. It's free money. But okay, well, I've got the tech sitting here. Is there a tech to EPUB? Is there something that'll just do this? And the answer is no. Someone said, well, you could start by hacking latex to HTML. But of course, what it produces is not what Marty had in mind. I was also grading papers, March is paper reading month for me. I was on three program committees and it sure would have been nice to read some of these papers on the iPad. What I had was PDF, which I'll get to in a moment, of course. So there's this early versus late layout tension. The early layout, we all know and love. This is what I learned in the 80s. Tech, runoff, if you go through the 70s, and T-Rough versus HTML, XML, we'll figure out at the last minute, grandma wants this font and this size and we'll just lay it out for her and that's how we read web pages and iBooks and that sort of stuff. But really, I want Marty to do this. I don't want grandma to do it. I don't care if she likes Garamond bold. Marty, I'm a fascist in this case. I want Marty for large values of Marty to figure out what looks beautiful and to present them that way and I think the authors probably want that too. So my goals for the project, I wanted Marty to design the pages and again, large values of Marty. Typographic fascism. Each paper needs to be laid out separately for portrait and landscape. It's a different format. This thing is sort of 1024 by 768 or like that. It actually isn't, you can't just reverse the numbers because there's a little header on the top that you want to keep, which means that's different. I do want for grandma a large type addition and Marty knows how to make those too. So it would be nice to do this and it'd be nice to easily port old tech documents to this so that we could all be looking at beautiful layouts on the iPad. PDF did not appear to me to be the solution. Now, given two weeks, I didn't do a whole lot of related work reading. So it was entirely possible this talk was going to be totally redundant and maybe it is. PDF as far as I'm concerned produces pretty nice looking 8.5 by 11 or A4 papers that I print out and read. I don't want to read them on the iPad. You have to sort of scan this Fresnel lens up and down like a 1960s cataract patient or and reading in a column. Page two is below page one and you sort of halfway up and down. That's not it. It doesn't know about portrait or landscape. It doesn't know what to do the right thing and there's no large type option. Now I listened this morning with interest to what's happened to PDF and maybe I'm all wrong about that. We'll get back to that which is fine. I'm okay with that. So when to do this? Well you can run latech on the iPad. Heck the firewalls book runs through tech. It's 480 pages. It goes a second and a half on a modern Pentium which is just unbelievable. If you told me that in 1985 I would have said there's no way you could lay out a book in a second and a half. The DVI to whatever obviously takes a bit longer. How about sending the DVI to the iPad for processing? That's kind of close. You'd have to have the fonts lying around and stuff but that's doable. Or a special version of tech on the iPad. This was a paper done last year here that suggested something along these lines. It looked a little busy to me but maybe a good way to go. Or do you just pre-compute the images? And that's the way I went. Pre-compute every image for everything grandma is going to want to ask for. That means there's a portrait version, a landscape version, a large type portrait version and a large type landscape version. All of them laid out with separate style files. So it might be quite different. Download a bundle and the definition of that bundle ought to be if we like this idea ought to be standardized somehow. And then a proof of concept iPad reader. My experience with programming iPhones and iPads is now eight days old. I've been programming in C for 20 years and the guys who said that it's just like C. It's just almost completely unlike C. But I have an iPad reader working. It's not Tangle and Weave but Tangle and Weave's ugly evil stepsister hack that makes this available to you today. But that's okay. It's proof of concept. So it's strictly proof of concept. Don't push this too far. The code is starting new. The beautiful layouts that I laid out are not quite beautiful. Again, I'm not Marty. You're Marty. You can figure it out. And some of the code wasn't working till last night. There's also the quandary when you're in a rush, you want to get a program done by next Monday. Do you just sit down? It is sort of like C. Do you just sit down and write the structs and mallocks and do the C? Or do you back off a little bit and learn how it's supposed to be done and maybe get it done? So there's this quick way that might be efficient or not. And then there's the longer way we actually learn something. For the astronomers in the crowd, you may know that if you want to grind your own mirror, I don't know if people do this anymore, but it used to be. If you wanted to grind an eight-inch mirror and you'd never ground a mirror before, the fastest way to grind an eight-inch mirror is to grind a six-inch mirror first and then an eight-inch mirror. You'll get done before you do an eight-inch mirror. And so it's the same question of how much do you do? Also, I never was very good at tech and what I do know is 20 years old. So if I want to change the paper size, I'm in there hacking article.sty and art10.clow and these things. And they all have this ominous stuff at the beginning saying, don't change this. Go change the class generation program, which I know nothing about. I suspect there's some place I can go where I just say, change the page size to this, go, and all this magic comes out. But I didn't know that. So do I take time doing that or do I just hack what I'm doing? It turns out it would have been much faster to know what I'm doing. I hadn't heard of the geometry package, which would have made this so much easier. You know, Wednesday, well, I've got the iPad sort of working, so Wednesday I'll try to change this into beautiful stuff. That could have been Wednesday morning. I still have it shifted wrong, but I'm going to go back and fix it. The other problem is when research yields 1,000 blooms, finding the right bloom isn't always easy. I went first to DVI to Bitmap because I wanted to generate bitmaps. I'm guessing this is pretty old and hasn't been touched for a while, but I didn't know that at the time. So I was getting black and white bitmaps. It looked a lot like the output I used to get off my Epson dot matrix printer. And that's what I was going to show you folks today because, heck, you're the Marty, you can sort of envision what it would look like. And after a day of looking at this crap, oh, by the way, all of my specials, my PostScript specials didn't work either. So I said, well, let's do DVI PS because, gee, I could do anti-aliasing fonts and grayscale somehow. They give GhostView enough options and it'll probably come out looking almost as good as Apple stuff. I was one guy in one week trying to compete with all of Cupertino's cleverness. And then I noticed in passing DVI PNG, which was exactly what I wanted. And everything, it's something that produced TRIM output. It had just the options I wanted. It worked great. Wouldn't it have been nice if DVI to Bitmap would say, not, this isn't the official documentation, but you don't want to be here, Bozo. Go look at DVI to Bitmap. That would have saved me a half a day. So I've got a demo here. How am I doing? Pretty well. What to show? Well, I thought, gosh, I'll just lay out the tech book, a nice familiar thing. And I went to the web page and had forgotten the admonition by You Know Who who says, don't print out the tech book, please. So I didn't do the tech book. Well, how about the firewalls book? Okay. Started running that through it. Turns out, drops core in DVI PNG. Well, I'm in a hurry. I'm not going to go find that. I can find it. I think I know basically what it's missing. And so I've got to find a book. Went to Gutenberg project, thought of Huck Finn and said, no, how about on the origin of the species? So that's what I got. Otoots, as I call it. And I took one of my old papers. So there's a paper and a book just to see what it looks like. Now the demo is, I'm going to show you, is on the iPad simulator, which is on this book. I also have it loaded in here. And if you ask me afterwards, you can actually touch and fondle my iPad and try it yourself. The user interface is extremely crude because I didn't have much time. None of this swiping or clever page things. It just goes. But it gives you an idea. It's proof of concept. And so let's see. With a little luck, this is just going to go not like that. Okay. What do I do? Well, see, I'm usually pretty good at swapping these things in and out, but not always. So come here. We want this guy and we're going to move him over to here. Oh, I don't even know if this works in this one. So we'll give it a try. In fact, we'll start it afresh. Here we go. Simulator start. Boom. It's compiling right here. No errors. What's up? It's stupid. On the origin of the species. And if you click on the right side, it goes to the next page. This was I basically took the text, cleaned it briefly. Barbara, this is not a final book format. This is just Gutenberg text with a few things on it. And you can see I got the top a little wrong. I think geometry will fix that for me. Having trouble reading it, you click at the top and you get the large type version. Large type in this version is 12 point, but maybe it should be something a little bigger. And you can go through here and chapter one. And oh my goodness, Euler's equation. Did you know that was in origin of the species? That is used everywhere. It just keeps showing up. You thought he was just a biologist. And what's more, I found this delight, which you will never find in the EPUB version. You go a little further. We've got Maxwell's equations and the diffusion equation. So there you go. It all just lays out. It's in gray scale. It actually, I think, I mean, you can't tell up here. I think on here it looks just as good as Apple's stuff. Actually better because it's got Don laying out the paragraphs and you folks doing the rest of the stuff, sort of. And of course, I'm not sure this is going to work because I'm not sure it works on the auxiliary screen. If you go to this version, oh look, it's laid out in two column because it's a wide screen. And you can go back to previous pages. Now there's an interesting question. I'm in a different part of the book now. When you rotate, which one should it go to? I haven't really solved that. I do this proportional thing, but someone has to think about how that works. Anyway, so we've got, it's now landscape. I think we're a little bit beyond, see page navigation is just clicking, you know, what do you want? It's been a week. There we go, chapter anyway. You get the idea. And I also have, let's switch back to vertical, which you don't have to do. I have, if you click in the middle, a paper, a regular academic paper. This one I published about 10 years ago on visualizing the internet. And it's about the right size, shows networks, nice pretty pictures. But of course, with a good reader, you'd be able to click on that picture and zoom in indefinitely and so on. Because let's face it, we're not just dealing with a book here. This is something that's better. And of course, go back to landscape and, oh, well, double-sided seems to be about right for this. And you can go through and I think there are even some over-full H boxes at the end. Oh, there was, actually there was a rendering issue there, but who cares? Oh, vertical lines show up. So that's my demo. And you're welcome to try that. Those are the only two documents in there. There's no nice selection and download and stuff. It has the two preloaded in there and not the whole thing. But it'll give you, it gives you the idea. Now we go down here back to our regularly scheduled. Oh, this is going to be so crude. It's going to start at the beginning again, isn't it? Oh, no. No, there it is. How about that? OK. Cleaner than most demo switches, I think you'll agree. So zooming in on images would be nice and video. Little words for dictionary, glossary, the iBook. Apple iBook you go and tap something and a little dictionary option comes up and you can look up words. I have Podcain of Mars and I looked at three words and none of them were in the dictionary. But they should be and they should be hooked in with a glossary in the index and you can imagine all this sort of thing going on. And I guess you do it with little marks in the DVI somehow interacting with it. Footnote navigation. I have Dave Barry's book in here, his latest book. And you tap on a footnote and it goes to the back and you tap on 22. You go back and you got a bunch of numbers and you read 22. And if you suddenly forget it was 22, there's no back to where I was button. You have to start at 21, 20, no. Oh, 22, there. That's where I was. Footnote navigation. I'd also like to have an error code if you try to go beyond the page and I was hoping to have Don record. Nope. And just have that be the error thing. So I don't think he's here at the moment but if someone can record him saying no, I'd like to use it for this. There are other problems. Obviously, I'm going to make geometry work real soon now. Other latex styles need new sizes. It was frustrating. If you're doing letter size or A4, that's fine. But nothing in there had a paper size of iPad or iPad landscape. And it's time to put that in there. And as I say, this is not the same as this because there's a little 17 pixel band across the top. So you got to adjust it. And I know you fuzzy people care about stuff like that. The styles can be a bit over constrained. If you're tired of fixing over full H boxes, imagine that now when you say go to compile your document, you not only have your regular letter size one but you have four other layouts all complaining about sizes and layouts. This may be over constrained but I know we can handle it. And there are probably tools that one could put in there to do a better job. It certainly would be nice to have Kindle and Nook additions. I suspect that would be pretty easy. I don't know if they go into landscape mode or not. The iPhone, the new iPhone is now twice the resolution of the iPhone that I have in my pocket. One could imagine that the next iPad will do the same thing. So we'll need a high res version of it but we'll just look better, won't we? Page numbers. If you use that sort of an interesting thing, it could use a much better iPad app than my one week old convective C or whatever it is attempt. So what should I do with this? Should I keep going? Is this great? Should I learn Apple programming which is one of the reasons I did this? Do we try to get people to publish their papers in this format too? Do I get clearance from my software from AT&T? I haven't tried that yet. They're going to say, you want to clear what? This is not the main. Or do we let the PDF folks do it? If PDF really is the answer, then the PDF reader is going to do all this stuff sooner or later but I'm wondering if they'll get it right. So do we fork off and do it? I don't know. Also, ITech, that's what I call the demo, ITech, get it? The ITech, this bundle of how you put things could be a very easy GZIP directory structure, would need support and definition and stuff and we can come up with something pretty easily. So rounding third here, the permuted index, I pulled it out for my hacking this time. I looked up, I consulted it four times and it helped once. The other three, I just couldn't find the words that matched which was my first problem with it. So I don't know if that was a successful research project but it was good to do. This seems like a useful idea. I've actually inclined maybe to download all of the origin of the species to this app before I leave for my flight home and read it using my app. It certainly is a pleasant thing to do. Suggestions and feedback are welcome. Have I missed things? Am I wasting my time? I'm willing to put more work into this idea though you don't want me doing the style stuff. You probably don't want me doing the Apple iPad stuff either because someone who knows how to do this stuff can rattle it off much faster than I can. I'd love to hear what you think and I thank you for your attention and welcome questions. And that's what the talk is about. Thank you very much. Questions or comments? Where did you get the microphone? Yes, Mike? At the last talk meeting in Cork there was some behind the scenes discussion of how to make reflowable PDF in tech. Reflowable PDF is the one which can change pagination if you turn it, if you change it. There was even a mailing list but the problem is that nobody was able to create the application which would work. So your approach when you just pre-compute several sizes. We discussed, by the way, somebody told us this is the way. The more I see that, I see that you are absolutely right. Probably the good way for us to create the... So it's exactly what I would suggest you to contact Peter Flynn. Unfortunately, he's not here. He could make it because you are the person he wants to talk to. Okay. Would someone send me email and if you can't find me I don't want to talk to you anyway. That's great. It's pretty clear that someone who's not very good at tech and not very good at Apple can do this in a week and a half that this is not that hard to do. Yeah, yeah, yeah. Send me email telling me his name and I'll be happy to chat with him and see what should happen and of course welcome other suggestions. Someone else? Yes? I'd like to congratulate you on doing in two weeks what it took Wired Magazine and Adobe a couple of weeks, a couple of months to do. I don't know if you followed the Wired Magazine app. No, I haven't. Okay. The short story is they took an entire magazine done in design, floated out twice, once in landscape format, once in portrait format, formatting the pages by hand for each view, stuffed all of those into image files, wrapped it up with a page directory structure, done an XML, stuff that into an app and sold it as an app for $2.99 a copy. Cool. Yeah, but the problem is the magazine is 500 megs. Well, okay, so I just did the first 20 pages of Origin of the Species. If you do the whole thing, then all the layouts put together and it's a big pile of PNGs comes to about 300 megabytes. This is a 64 gigabyte iPad. It's going to take a while to fill it up and if I don't want the large type, cut that in half. So I've decided in the last 20 years CPU speeds and disk sizes have just changed dramatically. I'm not worried about it. But also the other thing is that this was a pretty good demo. Remember, there is absolutely nothing behind the curtain. They had to make it work and they care about their layout and so on. But I don't think it's that hard, especially if you really know what you're doing. My concern with doing bitmap images is you're going to run it up against a huge, countless number of permutations of different screen sizes and proportions and eventually you'll either run out of the energy to support them or you'll run out of the energy. It could be a problem. You might just do iPads for now. And again, the large type, switching to the large type was just my answer to grandma wanting to click a bigger font. My web pages, which I redesigned for the first time in 15 years, uses CSS that honors grandma's font size because I've had too many web pages where I can't read them. And so I want to honor that ability. It's not a bad idea, but who knows? Anyway, I think the approach is doable. It takes a while to download too. And it doesn't compress well because the PNGs are already compressed. Other questions? We've got two here. We have time to get up and time to go. Lots of time. Nice. Impressive. Oh, thank you. Really nice. But I suggest a completely different approach. Excellent, excellent. We have time. Let's hear it. I don't know how much you know about HTML5, Canvas, JavaScript. My idea is simply put the text into the browser. Do it all in the browser. Let the browser render the text file. Let it break the paragraph. We have already a hypernation algorithm running in JavaScript. We probably already have the par builder in JavaScript. We know that we've just seen that the browser can render mathematics beautiful. Jonathan here has done much for web fonts. So we can use open type features probably completely. We will live to see the day where we can use complete open type mass by the browser. So forget about bitmaps. Do it all in the browser because then your book works on the iPads, on the iPhone, on Android, or maybe even on Nokia. So it works everywhere. So that's interesting. So I guess you want a web to JavaScript converter because you actually want to run tech and latech in the browser, I assume. Which means you're going to have to have all the stuff, all the auxiliary files you pull in. Now it's doable and it doesn't take that long. Do I mind if there were a 30 second delay before I start reading a book? Maybe not. So I think that's a feasible approach and I don't know what the right answer is. I know this seems to work right now very well but you may be right. Also HTML5 is still gelling, of course. So we'll see how that goes. I want multi-column. But I think that's possibly right, yeah. I just want to second his suggestion. In fact, the origin of the species available already on the app store. We're using HTML5. I mean, we really have to get out of the custom of doing bitmaps and bitmaps and bitmaps and going to a vector. Vector is the direction to go. So another vote for a late computation or a late computation of the early layout. You've got it right there. Okay. Thanks. I was thinking about something that's kind of a compromise between the two. Would you put on the iPad something that would do your image capture that you're doing in the background instead of packaging the images, let the images be formed within your own app? So it would come from the DVI files then? Yeah. Yeah, I think that might be a good way to do it. Well then the resolution wouldn't matter anymore because it would happen on whatever machine it was running. Well, yeah, you'd still want to have a portrait in the landscape version. Right? You're going to have different layouts because you should. Okay. Yeah, because Marty. Right, right, right. Yeah, it's a different form factor. But it may be. So now we've got votes for all three places and that's fine. I was raising. Maybe we should do a show on that. Oh, I'd like to hear that. Oh, no, no, no, no. You have to use the mic. Yeah, the iPad can support PDF, right? So your step of converting PDF, PNG, is unnecessary. We convert PDF to PDF. If you have a PDF reader that doesn't put enough jobs, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it. Yeah, you can use it.
 And yes, I am using Keynote.  I did try using Slitech for a little while and decided that it wasn't quite the same  for me, then I give a lot of talks.  So this has been working well.  Hello.  And so, okay, we'll give this a go.  I'd like to thank you all for having a slot for me.  I learned about this meeting about two weeks ago from Barbara.  But there had been something on my mind I'd wanted to do along this field.  So I said, ooh, I could give a paper on that.  And I said, well, it's two weeks before the conference.  There's no way they'll have a slot.  And sent mails.  I dashed off and titled and abstract and got back, sure, we'll fit you in.  And even on the day you need to be fit in, because I can't stick around, unfortunately.  So all I had to do was get a travel clearance, which arrived today.  And by the time, between the time I submitted the travel clearance, I work at AT&T Labs,  and the time my boss said, oh yeah, that's been approved, the price for the airfare had  gone up 600 bucks.  So I paid almost as much money as it costs to fly from Newark to Sydney to get here today,  which means I don't like to do that.  I'm a pretty cheap date, usually, but it means I'm flying first class out and back.  I even bought one of those little power adapters for use in first class.  The two legs out, the first one, the brand new first class seats didn't have any plugs  for them.  And for the second leg, it was broken.  So I didn't get to do anything there.  Anyway, United thanks you.  There was no question about my flying first class, though I bought Coach.  It was a $1,600 seat, which is not usual.  Anyway, I'm only here for a day.  And this is my first tech conference since, I think, 1988.  My first real paper was at tech when I did the Pre-Muted Index for Tech some 25 years  ago.  I don't know if any of you use it.  It's still there.  You do use it?  Not now.  Well, so we'll get back to that in a moment.  My problem was that I had learned tech and I'd just gotten learned tech.  I started using tech.  I don't know who knows it.  Even Don seems a little sketchy on some of the commands.  But I'd hack these things and I'd have epic battles where I just want to move this over  one M. And you add spaces and it won't do it and so on.  And I'd spent two days fiddling with this stuff.  And my problem was that the answer to my question was the string command, but I didn't know how  to ask the question or find where in the tech book it was.  And that's what brought me to try to do a summary of every command in the whole thing,  trying to use words that made sense so that if you sort of knew the right words, you might  guide you to the right thing.  And I submitted it and I guess it's still available.  I don't know.  It was generated on a Plan 9 operating system, which is long gone, but it could be easily  resurrected if anyone cared.  But what this really did was open my eyes to typography, that beautiful layout is important.  Ligatures.  Who knew?  I'd been reading for 30 years and I didn't know f's were connected to i's.  And I went back, wait a minute, can this be true?  And would take some of my favorite books down and oh yeah, look at that.  They're glued together.  I never noticed that.  But so it really gave me quite an appreciation and a huge amount of humility in terms of  this is something you can try.  It's like user interfaces.  Everyone likes to try it, but not many are very good at it.  And in fact, one of the reasons I have a Mac here.  I also became a nitpicker.  In my recent years, I review a lot of papers and my comments often slide into and by the  way, this layout is crazy.  Quote, don't use footnote in your books, Don.  I put that in some of my reviews because a lot of people abuse them.  And nowadays people are including fuzzy JPEG graphs.  These are sometimes in visualization papers with three point font.  And it's just awful.  Anyway, so I became a nitpicker.  I went on, this was just before I went off to Bell Labs where I learned how to be somewhat  of an academic.  And it served me well.  I wrote a firewalls book with Steve Belevin in 1994, you folks may have heard of.  We invented a style for the book but said, okay, Addison Wesley, have a shot at it.  And Marty Rabinowitz was the typographer there and he told us how to fix things and we did  that.  But despite having done the second edition and published a number of papers, I haven't  done much text since then until about two weeks ago when you folks said yes and suddenly  I had to show something prototype.  So I have been burning the midnight oil and telling my wife no, I don't have time to go  for a walk.  This program has to run by next Monday at 2 p.m. Pacific time.  And I made it but it's a much better demo now than it was yesterday at this time.  So I am an early adopter.  My iPad arrived, I ordered it by mail.  The UPS guy arrived on the day it first appeared.  He was going around Somerset County, New Jersey handing these out to many people.  And here you are, yeah, I got a lot more.  And I started reading it and really realized that this changes everything.  It's not a big iPhone, it's not a laptop, it's something new.  It's a lovely way to read a book which means it changes the way you go to a bookstore,  at least for me.  When I go to a bookstore I'll buy junk books that I know I'm going to read once.  But now that I have the iPad, some books I want to own and have a treasure and have people  sign and so on and I'm going to reread them and give them to my kids.  And others like today's latest take on cosmology.  I'm not going to want to read that in 20 years.  That's like an old textbook.  I just don't need, I just want to read it once.  And why would I buy some pulp when I could just put it into the iPad, which I don't want  to forget, you know, just put it in here and now it's ready to read in some form or another.  The typography in iBook and the Kindle app on the iPad are okay.  I mean, you can read it, I've read about it a dozen books since late March.  But they're not great.  And I also thought, gosh, why would a book ever go out of print again?  You just store it on disk.  Well, heck, you know, the firewalls book, the first edition is still in print, even though  the second edition came out in 2003.  There are people who are still buying a book that talks about TIS's toolkit.  You know, they're gone, it's decades gone, but they're still there and I thought, gee,  I'm willing to charge them a buck 99 for the first edition.  We could split it three ways between the publisher, the authors, and Apple.  It's free money.  But okay, well, I've got the tech sitting here.  Is there a tech to EPUB?  Is there something that'll just do this?  And the answer is no.  Someone said, well, you could start by hacking latex to HTML.  But of course, what it produces is not what Marty had in mind.  I was also grading papers, March is paper reading month for me.  I was on three program committees and it sure would have been nice to read some of these  papers on the iPad.  What I had was PDF, which I'll get to in a moment, of course.  So there's this early versus late layout tension.  The early layout, we all know and love.  This is what I learned in the 80s.  Tech, runoff, if you go through the 70s, and T-Rough versus HTML, XML, we'll figure out  at the last minute, grandma wants this font and this size and we'll just lay it out for  her and that's how we read web pages and iBooks and that sort of stuff.  But really, I want Marty to do this.  I don't want grandma to do it.  I don't care if she likes Garamond bold.  Marty, I'm a fascist in this case.  I want Marty for large values of Marty to figure out what looks beautiful and to present  them that way and I think the authors probably want that too.  So my goals for the project, I wanted Marty to design the pages and again, large values  of Marty.  Typographic fascism.  Each paper needs to be laid out separately for portrait and landscape.  It's a different format.  This thing is sort of 1024 by 768 or like that.  It actually isn't, you can't just reverse the numbers because there's a little header  on the top that you want to keep, which means that's different.  I do want for grandma a large type addition and Marty knows how to make those too.  So it would be nice to do this and it'd be nice to easily port old tech documents to  this so that we could all be looking at beautiful layouts on the iPad.  PDF did not appear to me to be the solution.  Now, given two weeks, I didn't do a whole lot of related work reading.  So it was entirely possible this talk was going to be totally redundant and maybe it  is.  PDF as far as I'm concerned produces pretty nice looking 8.5 by 11 or A4 papers that  I print out and read.  I don't want to read them on the iPad.  You have to sort of scan this Fresnel lens up and down like a 1960s cataract patient  or and reading in a column.  Page two is below page one and you sort of halfway up and down.  That's not it.  It doesn't know about portrait or landscape.  It doesn't know what to do the right thing and there's no large type option.  Now I listened this morning with interest to what's happened to PDF and maybe I'm all  wrong about that.  We'll get back to that which is fine.  I'm okay with that.  So when to do this?  Well you can run latech on the iPad.  Heck the firewalls book runs through tech.  It's 480 pages.  It goes a second and a half on a modern Pentium which is just unbelievable.  If you told me that in 1985 I would have said there's no way you could lay out a book in  a second and a half.  The DVI to whatever obviously takes a bit longer.  How about sending the DVI to the iPad for processing?  That's kind of close.  You'd have to have the fonts lying around and stuff but that's doable.  Or a special version of tech on the iPad.  This was a paper done last year here that suggested something along these lines.  It looked a little busy to me but maybe a good way to go.  Or do you just pre-compute the images?  And that's the way I went.  Pre-compute every image for everything grandma is going to want to ask for.  That means there's a portrait version, a landscape version, a large type portrait version and  a large type landscape version.  All of them laid out with separate style files.  So it might be quite different.  Download a bundle and the definition of that bundle ought to be if we like this idea ought  to be standardized somehow.  And then a proof of concept iPad reader.  My experience with programming iPhones and iPads is now eight days old.  I've been programming in C for 20 years and the guys who said that it's just like C. It's  just almost completely unlike C. But I have an iPad reader working.  It's not Tangle and Weave but Tangle and Weave's ugly evil stepsister hack that makes this  available to you today.  But that's okay.  It's proof of concept.  So it's strictly proof of concept.  Don't push this too far.  The code is starting new.  The beautiful layouts that I laid out are not quite beautiful.  Again, I'm not Marty.  You're Marty.  You can figure it out.  And some of the code wasn't working till last night.  There's also the quandary when you're in a rush, you want to get a program done by next  Monday.  Do you just sit down?  It is sort of like C. Do you just sit down and write the structs and mallocks and do  the C?  Or do you back off a little bit and learn how it's supposed to be done and maybe get  it done?  So there's this quick way that might be efficient or not.  And then there's the longer way we actually learn something.  For the astronomers in the crowd, you may know that if you want to grind your own mirror,  I don't know if people do this anymore, but it used to be.  If you wanted to grind an eight-inch mirror and you'd never ground a mirror before, the  fastest way to grind an eight-inch mirror is to grind a six-inch mirror first and then  an eight-inch mirror.  You'll get done before you do an eight-inch mirror.  And so it's the same question of how much do you do?  Also, I never was very good at tech and what I do know is 20 years old.  So if I want to change the paper size, I'm in there hacking article.sty and art10.clow  and these things.  And they all have this ominous stuff at the beginning saying, don't change this.  Go change the class generation program, which I know nothing about.  I suspect there's some place I can go where I just say, change the page size to this,  go, and all this magic comes out.  But I didn't know that.  So do I take time doing that or do I just hack what I'm doing?  It turns out it would have been much faster to know what I'm doing.  I hadn't heard of the geometry package, which would have made this so much easier.  You know, Wednesday, well, I've got the iPad sort of working, so Wednesday I'll try to change  this into beautiful stuff.  That could have been Wednesday morning.  I still have it shifted wrong, but I'm going to go back and fix it.  The other problem is when research yields 1,000 blooms, finding the right bloom isn't  always easy.  I went first to DVI to Bitmap because I wanted to generate bitmaps.  I'm guessing this is pretty old and hasn't been touched for a while, but I didn't know  that at the time.  So I was getting black and white bitmaps.  It looked a lot like the output I used to get off my Epson dot matrix printer.  And that's what I was going to show you folks today because, heck, you're the Marty, you  can sort of envision what it would look like.  And after a day of looking at this crap, oh, by the way, all of my specials, my PostScript  specials didn't work either.  So I said, well, let's do DVI PS because, gee, I could do anti-aliasing fonts and grayscale  somehow.  They give GhostView enough options and it'll probably come out looking almost as good as  Apple stuff.  I was one guy in one week trying to compete with all of Cupertino's cleverness.  And then I noticed in passing DVI PNG, which was exactly what I wanted.  And everything, it's something that produced TRIM output.  It had just the options I wanted.  It worked great.  Wouldn't it have been nice if DVI to Bitmap would say, not, this isn't the official documentation,  but you don't want to be here, Bozo.  Go look at DVI to Bitmap.  That would have saved me a half a day.  So I've got a demo here.  How am I doing?  Pretty well.  What to show?  Well, I thought, gosh, I'll just lay out the tech book, a nice familiar thing.  And I went to the web page and had forgotten the admonition by You Know Who who says, don't  print out the tech book, please.  So I didn't do the tech book.  Well, how about the firewalls book?  Okay.  Started running that through it.  Turns out, drops core in DVI PNG.  Well, I'm in a hurry.  I'm not going to go find that.  I can find it.  I think I know basically what it's missing.  And so I've got to find a book.  Went to Gutenberg project, thought of Huck Finn and said, no, how about on the origin  of the species?  So that's what I got.  Otoots, as I call it.  And I took one of my old papers.  So there's a paper and a book just to see what it looks like.  Now the demo is, I'm going to show you, is on the iPad simulator, which is on this book.  I also have it loaded in here.  And if you ask me afterwards, you can actually touch and fondle my iPad and try it yourself.  The user interface is extremely crude because I didn't have much time.  None of this swiping or clever page things.  It just goes.  But it gives you an idea.  It's proof of concept.  And so let's see.  With a little luck, this is just going to go not like that.  Okay.  What do I do?  Well, see, I'm usually pretty good at swapping these things in and out, but not always.  So come here.  We want this guy and we're going to move him over to here.  Oh, I don't even know if this works in this one.  So we'll give it a try.  In fact, we'll start it afresh.  Here we go.  Simulator start.  Boom.  It's compiling right here.  No errors.  What's up?  It's stupid.  On the origin of the species.  And if you click on the right side, it goes to the next page.  This was I basically took the text, cleaned it briefly.  Barbara, this is not a final book format.  This is just Gutenberg text with a few things on it.  And you can see I got the top a little wrong.  I think geometry will fix that for me.  Having trouble reading it, you click at the top and you get the large type version.  Large type in this version is 12 point, but maybe it should be something a little bigger.  And you can go through here and chapter one.  And oh my goodness, Euler's equation.  Did you know that was in origin of the species?  That is used everywhere.  It just keeps showing up.  You thought he was just a biologist.  And what's more, I found this delight, which you will never find in the EPUB version.  You go a little further.  We've got Maxwell's equations and the diffusion equation.  So there you go.  It all just lays out.  It's in gray scale.  It actually, I think, I mean, you can't tell up here.  I think on here it looks just as good as Apple's stuff.  Actually better because it's got Don laying out the paragraphs and you folks doing the  rest of the stuff, sort of.  And of course, I'm not sure this is going to work because I'm not sure it works on  the auxiliary screen.  If you go to this version, oh look, it's laid out in two column because it's a wide screen.  And you can go back to previous pages.  Now there's an interesting question.  I'm in a different part of the book now.  When you rotate, which one should it go to?  I haven't really solved that.  I do this proportional thing, but someone has to think about how that works.  Anyway, so we've got, it's now landscape.  I think we're a little bit beyond, see page navigation is just clicking, you know, what  do you want?  It's been a week.  There we go, chapter anyway.  You get the idea.  And I also have, let's switch back to vertical, which you don't have to do.  I have, if you click in the middle, a paper, a regular academic paper.  This one I published about 10 years ago on visualizing the internet.  And it's about the right size, shows networks, nice pretty pictures.  But of course, with a good reader, you'd be able to click on that picture and zoom in  indefinitely and so on.  Because let's face it, we're not just dealing with a book here.  This is something that's better.  And of course, go back to landscape and, oh, well, double-sided seems to be about right  for this.  And you can go through and I think there are even some over-full H boxes at the end.  Oh, there was, actually there was a rendering issue there, but who cares?  Oh, vertical lines show up.  So that's my demo.  And you're welcome to try that.  Those are the only two documents in there.  There's no nice selection and download and stuff.  It has the two preloaded in there and not the whole thing.  But it'll give you, it gives you the idea.  Now we go down here back to our regularly scheduled.  Oh, this is going to be so crude.  It's going to start at the beginning again, isn't it?  Oh, no.  No, there it is.  How about that?  OK.  Cleaner than most demo switches, I think you'll agree.  So zooming in on images would be nice and video.  Little words for dictionary, glossary, the iBook.  Apple iBook you go and tap something and a little dictionary option comes up and you  can look up words.  I have Podcain of Mars and I looked at three words and none of them were in the dictionary.  But they should be and they should be hooked in with a glossary in the index and you can  imagine all this sort of thing going on.  And I guess you do it with little marks in the DVI somehow interacting with it.  Footnote navigation.  I have Dave Barry's book in here, his latest book.  And you tap on a footnote and it goes to the back and you tap on 22.  You go back and you got a bunch of numbers and you read 22.  And if you suddenly forget it was 22, there's no back to where I was button.  You have to start at 21, 20, no.  Oh, 22, there.  That's where I was.  Footnote navigation.  I'd also like to have an error code if you try to go beyond the page and I was hoping  to have Don record.  Nope.  And just have that be the error thing.  So I don't think he's here at the moment but if someone can record him saying no, I'd like  to use it for this.  There are other problems.  Obviously, I'm going to make geometry work real soon now.  Other latex styles need new sizes.  It was frustrating.  If you're doing letter size or A4, that's fine.  But nothing in there had a paper size of iPad or iPad landscape.  And it's time to put that in there.  And as I say, this is not the same as this because there's a little 17 pixel band across  the top.  So you got to adjust it.  And I know you fuzzy people care about stuff like that.  The styles can be a bit over constrained.  If you're tired of fixing over full H boxes, imagine that now when you say go to compile  your document, you not only have your regular letter size one but you have four other layouts  all complaining about sizes and layouts.  This may be over constrained but I know we can handle it.  And there are probably tools that one could put in there to do a better job.  It certainly would be nice to have Kindle and Nook additions.  I suspect that would be pretty easy.  I don't know if they go into landscape mode or not.  The iPhone, the new iPhone is now twice the resolution of the iPhone that I have in my  pocket.  One could imagine that the next iPad will do the same thing.  So we'll need a high res version of it but we'll just look better, won't we?  Page numbers.  If you use that sort of an interesting thing, it could use a much better iPad app than my  one week old convective C or whatever it is attempt.  So what should I do with this?  Should I keep going?  Is this great?  Should I learn Apple programming which is one of the reasons I did this?  Do we try to get people to publish their papers in this format too?  Do I get clearance from my software from AT&T?  I haven't tried that yet.  They're going to say, you want to clear what?  This is not the main.  Or do we let the PDF folks do it?  If PDF really is the answer, then the PDF reader is going to do all this stuff sooner  or later but I'm wondering if they'll get it right.  So do we fork off and do it?  I don't know.  Also, ITech, that's what I call the demo, ITech, get it?  The ITech, this bundle of how you put things could be a very easy GZIP directory structure,  would need support and definition and stuff and we can come up with something pretty easily.  So rounding third here, the permuted index, I pulled it out for my hacking this time.  I looked up, I consulted it four times and it helped once.  The other three, I just couldn't find the words that matched which was my first problem  with it.  So I don't know if that was a successful research project but it was good to do.  This seems like a useful idea.  I've actually inclined maybe to download all of the origin of the species to this app before  I leave for my flight home and read it using my app.  It certainly is a pleasant thing to do.  Suggestions and feedback are welcome.  Have I missed things?  Am I wasting my time?  I'm willing to put more work into this idea though you don't want me doing the style stuff.  You probably don't want me doing the Apple iPad stuff either because someone who knows  how to do this stuff can rattle it off much faster than I can.  I'd love to hear what you think and I thank you for your attention and welcome questions.  And that's what the talk is about.  Thank you very much.  Questions or comments?  Where did you get the microphone?  Yes, Mike?  At the last talk meeting in Cork there was some behind the scenes discussion of how to  make reflowable PDF in tech.  Reflowable PDF is the one which can change pagination if you turn it, if you change it.  There was even a mailing list but the problem is that nobody was able to create the application  which would work.  So your approach when you just pre-compute several sizes.  We discussed, by the way, somebody told us this is the way.  The more I see that, I see that you are absolutely right.  Probably the good way for us to create the...  So it's exactly what I would suggest you to contact Peter Flynn.  Unfortunately, he's not here.  He could make it because you are the person he wants to talk to.  Okay.  Would someone send me email and if you can't find me I don't want to talk to you anyway.  That's great.  It's pretty clear that someone who's not very good at tech and not very good at Apple can  do this in a week and a half that this is not that hard to do.  Yeah, yeah, yeah.  Send me email telling me his name and I'll be happy to chat with him and see what should  happen and of course welcome other suggestions.  Someone else?  Yes?  I'd like to congratulate you on doing in two weeks what it took Wired Magazine and Adobe  a couple of weeks, a couple of months to do.  I don't know if you followed the Wired Magazine app.  No, I haven't.  Okay.  The short story is they took an entire magazine done in design, floated out twice, once in  landscape format, once in portrait format, formatting the pages by hand for each view,  stuffed all of those into image files, wrapped it up with a page directory structure, done  an XML, stuff that into an app and sold it as an app for $2.99 a copy.  Cool.  Yeah, but the problem is the magazine is 500 megs.  Well, okay, so I just did the first 20 pages of Origin of the Species.  If you do the whole thing, then all the layouts put together and it's a big pile of PNGs comes  to about 300 megabytes.  This is a 64 gigabyte iPad.  It's going to take a while to fill it up and if I don't want the large type, cut that in  half.  So I've decided in the last 20 years CPU speeds and disk sizes have just changed dramatically.  I'm not worried about it.  But also the other thing is that this was a pretty good demo.  Remember, there is absolutely nothing behind the curtain.  They had to make it work and they care about their layout and so on.  But I don't think it's that hard, especially if you really know what you're doing.  My concern with doing bitmap images is you're going to run it up against a huge, countless  number of permutations of different screen sizes and proportions and eventually you'll  either run out of the energy to support them or you'll run out of the energy.  It could be a problem.  You might just do iPads for now.  And again, the large type, switching to the large type was just my answer to grandma wanting  to click a bigger font.  My web pages, which I redesigned for the first time in 15 years, uses CSS that honors grandma's  font size because I've had too many web pages where I can't read them.  And so I want to honor that ability.  It's not a bad idea, but who knows?  Anyway, I think the approach is doable.  It takes a while to download too.  And it doesn't compress well because the PNGs are already compressed.  Other questions?  We've got two here.  We have time to get up and time to go.  Lots of time.  Nice.  Impressive.  Oh, thank you.  Really nice.  But I suggest a completely different approach.  Excellent, excellent.  We have time.  Let's hear it.  I don't know how much you know about HTML5, Canvas, JavaScript.  My idea is simply put the text into the browser.  Do it all in the browser.  Let the browser render the text file.  Let it break the paragraph.  We have already a hypernation algorithm running in JavaScript.  We probably already have the par builder in JavaScript.  We know that we've just seen that the browser can render mathematics beautiful.  Jonathan here has done much for web fonts.  So we can use open type features probably completely.  We will live to see the day where we can use complete open type mass by the browser.  So forget about bitmaps.  Do it all in the browser because then your book works on the iPads, on the iPhone, on  Android, or maybe even on Nokia.  So it works everywhere.  So that's interesting.  So I guess you want a web to JavaScript converter because you actually want to run tech and  latech in the browser, I assume.  Which means you're going to have to have all the stuff, all the auxiliary files you pull  in.  Now it's doable and it doesn't take that long.  Do I mind if there were a 30 second delay before I start reading a book?  Maybe not.  So I think that's a feasible approach and I don't know what the right answer is.  I know this seems to work right now very well but you may be right.  Also HTML5 is still gelling, of course.  So we'll see how that goes.  I want multi-column.  But I think that's possibly right, yeah.  I just want to second his suggestion.  In fact, the origin of the species available already on the app store.  We're using HTML5.  I mean, we really have to get out of the custom of doing bitmaps and bitmaps and bitmaps and  going to a vector.  Vector is the direction to go.  So another vote for a late computation or a late computation of the early layout.  You've got it right there.  Okay.  Thanks.  I was thinking about something that's kind of a compromise between the two.  Would you put on the iPad something that would do your image capture that you're doing in  the background instead of packaging the images, let the images be formed within your own app?  So it would come from the DVI files then?  Yeah.  Yeah, I think that might be a good way to do it.  Well then the resolution wouldn't matter anymore because it would happen on whatever  machine it was running.  Well, yeah, you'd still want to have a portrait in the landscape version.  Right?  You're going to have different layouts because you should.  Okay.  Yeah, because Marty.  Right, right, right.  Yeah, it's a different form factor.  But it may be.  So now we've got votes for all three places and that's fine.  I was raising.  Maybe we should do a show on that.  Oh, I'd like to hear that.  Oh, no, no, no, no.  You have to use the mic.  Yeah, the iPad can support PDF, right?  So your step of converting PDF, PNG, is unnecessary.  We convert PDF to PDF.  If you have a PDF reader that doesn't put enough jobs, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.  Yeah, you can use it.
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