 So, I'm very happy that you are here. I did this presentation a few months ago in London, and I plan to do a little update on the things I was involved. Unfortunately, I have spent a little bit of time then trying to set up a full workshop. So I hope you will forgive me, yes, my followers, that you will forgive me for having not totally updated. So, some features you will see released very soon enough. So, you came to a talk at the clash of the slashes or the division of the virus, that's it. My name is Theo and I just was talking this morning to somebody about my history and I had to admit I did not exist a year ago. Well, physically I did, but in the full community I was not known there, neither did I know the full community. So, I did something at that time, I was being a math teacher and so a lot of stuff you will see today is basically because I was a math teacher and frustrated about many things. So, my call about the clash of the slashes, this is what it's all about. If you have things like a slash, you will use it for many, many features. Probably for something like male, female, you will use it for regular expressions. You might use it for page number, whatever, from 80 or you will use it in a directory structure. Maybe you will use it in things like notations or think pretty nice American way to write down how far you are away from something, half a mile, or you can use it in options for my MS-DOS, if you still use it. You can use it for units, you can use it for so many things. I think this one was one, you can use it in spreadsheets and say cell A5 divided by 6, or you can use it for batching, you can use it for divisions. Well, you have so many slashes, even in the Unicode standards, if you look at how many slashes you have, you can use it for divisions, you can use it for fractions, you can use it for options, like I said, and the list goes on and on and on. The thing I was going to worry about is where actually that slash is coming from. We use it so many times and actually we use it for bad reasons. And while looking at the internet for the proper thing to do a division, I ended up a keyboard in Germany which does for me the right thing. It has a division sign. I don't know why you wanted to have a slash for divisions, but a slash for divisions is a bad thing. Mathematical divisions. This is not a division for me. Maybe for you it is, but actually it is more like this. That's a division, 3 divided by 4. Yeah, you can do it like this, but there is a reason for it. If I want to do a little bit more fun like the other thing, that's a slash, that's a three-quarter thing, that's not a mathematical expression, that's a number. Maybe you will say, well, that's 0.75, but for me it's a number and for mathematicians it's actually still a number. So what do we do? We have this for mathematics. We use a big line to make a division that has very good reasons because in mathematics you have long expressions to use a division and then use a slash and it doesn't work that way. What about this? I want to have 9 fourths divided by a half. I don't know how you would do that. You type something like this, or this. This is time-form divided by a half. If you're still keeping using that slash, find, try it, it will give you a completely different result. Everybody knows what's down here. So, fractions, fractions in life, they're not real. Why not? For me, three-quarter and 0.75 is a completely different story. You must say it's the same, it's not. And this is the reason why it's not the same in real life. For a three-quarter, for me it's something that will probably lay in three-quarter plus or minus one-eighth. As the Americans, they will say, yes, you're right. And you in real life know exactly what I'm talking about because if I say, let's walk half an hour, that's something completely different than walking 0.5 hours. To me, 0.5 hours. Half an hour, we have some more or less minutes. 0.75, if you're doing science, 0.75 will roughly lay between plus or minus five thousandths. That's a completely different range, isn't it? You write it as three-quarters or you write it as 0.75. Now, why is this completely different than as fractions are for real life? We use it for dividing the tasks. And nobody will argue with me that I'm 0.125 pizza. Have you ever seen people writing their Twitter messages that say, I got a 0.125 pizza today? Nope, he doesn't. That's a 0.8 pizza on the other half glass of water or whatever he wants. So, me being a math teacher and having reasons to work with fractions, especially if you're doing secondary school and the lower pass and the first influences of math, you're doing a lot on a lot of things with fractions in your mathematical expressions. And I was thinking, I want to do something with fractions in my code. I want to work with them. And that's not the real thing. I happened to talk with our cool six guy and he told me that cool six there had something very funny. It's called ratios. Yes, ratios are actually just fractions. Am I right? Yeah, yeah. So cool six does work with fractions, ratios. I'm not happy to hear that. So, what did I found on cpan for working with fractions? And I was, I will still admit, I was new to the code community and made some big mistakes at that time. I found a module written by this guy and I didn't know who Dave Cross was. And I said, I like your module but there's something wrong with it. So, me telling Dave Cross there's something wrong with it and we had some nice interesting discussions like I want to use your module but I want to extend it a little bit. And I learned extending pearl is, oh, you have your reasons how you do extending pearl. So, there was a thing like how to create a fraction in his module. It's just a nice thing to say I want a new half. That's how you create a half. But I want to do a more natural way of writing fractions. What if I wanted mixed fractions? The simple way to say mixed fractions. I'll show you what I mean with expressions. What about this? A new number of fraction thing with three parameters. Alright, one and two thirds. You say it's one and two thirds. Okay, that's... I'm one and two thirds, you know? I would say this is the way you make one and two thirds. But everybody knows if you're doing an extension on sub-proteins, never add your new parameters to the front. This is what I want to do. That's what will happen if you add more parameters to the front of it. So, it's going to be very nasty and luckily Dave Cross backed me up and he said if you go back one slide, let me go back one slide. Here. He said no one uses it anyways. So, that was more or less the way that... No matter what you do, you never fucking have somebody's code because nobody uses it. So, he said, alright, I'm way too bad. He said nobody uses it and I can do whatever I want. So, this one, two, three. Yes, I'm sorry, it won't have a new positional parameter in front of it. It will just do the natural way like everybody will do it. And this is how you make one, two, three. The whole thing of Dave Cross's module is that he actually built it in very, very lot of overloading. And one of the nice things with overloading is that he made it possible to interpret it constants. And when you do constants, you can actually now do these things you can print two-thirds and three-fifths and it will print nine-fifteen. Or you can say print a half times two-thirds and you will end up with one-third. That's what it will print. But I was not happy enough because I want my mixed fractions. So, that's what I've done. How to make mixed fractions. Now I can simply say print two minus one-quarter and two and a quarter minus one-and-a-half and it will say three-fourth. And I think this is a nice kind of cool syntax way where we always use the underscore to add things together in strings. You might discuss if I want to have a space in between. I will have a space in between. By the way, it will accept the space. I'm not happy. So, now the next thing. Because where did we start using that slash? Well, that slash is actually a thing we start using computers. Pre-computing. We had those nice things like a-half, a-quarter, three-quarters, the proper common things we had even there, the eights. And we stopped using them because we didn't know how to enter them. I was... We have equations. We have the horizontal. Yes, you can do it on a typewriter, but on your computer. That's fine. It's just a way of laying out. We have all kinds of nice fonts that will have different ways of displaying, either on top of each other or slanted. I just have a very nice one. But anyways, this is pre-computing area. But there is now also a, what I call, a post-esky era. Why still use all that rotten stuff and make it look ugly. The only way we still want that is because we're colors. But to be honest, I hate reading things like I see you in 0.5 hours. And people that are doing publishing, desktop publishing things will say, yes, let's go back to normal things. If you, and I want to have in my presentation, sorry, so that's the thing I have to excuse myself, I want to show you a demo where you could have a recipe for making cake or a nice recipe for making stew. Whatever you want to cook for, what does the book always say? Four persons. Yeah, well, let's have fun today and we are not with four people. But let's make it nice feast and have to multiply by six. Well, cookbooks and all these things are working with 0.5 liter, not with 0.5. Half into fractions. They will say half a cup or three quarter kind or any of those things. And I would make that what it would like to say I want to multiply this recipe by two or my wife and I are now just going to the house we used to have two kids in the house we will divide it by two and we'll still end up with the nice fractions. And post sq area needs to have unicode. I don't have pretty fractions. So what did I do? I extended the big cross module that will read the pretty fractions. All the unicode fractions is able to read. So you can now write in your code but you can write in your code 200 quarter minus one and a half is the same. But I'm a bad math teacher. I'm a very bad math teacher. Now the next thing, and that's why we come back to the thing of the clash of the slashes. This is something that's quite difficult to arrange. Powers. Mathematical powers and fractions the module still does only allow you to have introduced as powers of your fractions and it makes a lot of sense. It's very hard to do fraction powers of a fraction that's only working when you have a goblin method. No, wait. Actually in math how do we do that in math? In math we do this 3a plus a to the power of two this. It's possible to write it in math. Now there's a little problem. That thing there does simply not exist. The upper script division slash is not there. And if you go to math and I talk a little about my introduction the science we use in math to do the division is not the division slash at all. There's a few places where you can use that division slash. Look up your own math books from college maybe you can find them. The big ones from calculus there's only a few places where you can find the division slash and do one thing where it is used is there. No divisions in any math will be done with a slash except if you have a upper script slash needed for it. And it's not in the unicode table and there are bad reasons why it's not there. And the most stupid thing is we have slashes for anything. We have the solidest, we have back slashes we have division slashes we have even a friction slash for very good nice layout reasons. And we can do a little more things. Now what is unicode here? Unicode does have super scripts and subscripts super scripts and subscripts. You can build those fractions and you can think of hey I want to write like in the previous slides a to the power of two-fifth. We have all those super scripts there letting me view because unicode made some real strange decision of what would stand to the power of third where it's mostly being used in old ancient Eski where it's used to the power of three for cubic meters and cubic feet and square meters. I wish they had just filled in those gaps there one two and three but the one gap that's there in the unicode range is just simply not filled in empty not defined not being used so I hope soon enough I can do a proposal for that one single cliff that there will be an upper script division slash the only division slash allowed in math to fill up that gap and in summary that's used by what proper use of slashes it's not being used for mathematical divisions it's for real uses and more and well the last name missing super script of the slash for powers hence my thing of the clash of the slashes. You can use unicode fractions if you want to still there the version of they cross my extension will be available very very soon if you can use the funny things and you can use the running HTML if you'd like to do that all kind of nice things just to have proper fractions. Any questions? Can you go back to this sorry yes there are to the fifth range is there the sixth or there yes the quarters to half the eighth sixth the fifth and then you have the one seventh one nine and one ten and that's it being a math teacher I think okay I want the twelfth as well for very good reasons and we have plots any more questions for this nothing clear that was just for fun I know a very nice font building yes which one was it? Adobe made a very nice font for coders and it's called actually what was it called? vacation Adobe made a very nice fixed with font it has to do with code so I forgot anyways it doesn't have a very nice I was talking to you the other day where the fractional slash if you use it is actually not taking any space and even taking it more nice if you use a long fraction if you want twelve of seventeen for any reason twelve of seventeen is not a unico character if you use the let's say the upper script one the upper script two the fraction slash subscript one and subscript seven and that fraction slash will just combine the three character position on your screen that was all about wasn't it? I don't have it with me I will tell you I will have to look up for you anything else? no I have a little announcement a little announcement we have another break here then after the break we have two more sessions this is a general thing after the break we have two more sessions we will have lightning toss after that but this building is a university that I think seven people have graduated well it's holiday season the building is empty for these days except for today for graduation so we will probably end up that some people might use the catina as well as we do so be aware that we have more guests here and I think those are the official guests and we are just pouring their building so be kind and tell people don't mess up their nice day I think graduation day is more important than having full closure for them thank you for coming