 So, let me go to another solution that we came up for this problem that good documents are missing, that solution is called textbook companion or TBC in short. So, let us see more about it. Students are good in coding, but not documenting, but India has about 10 lakh engineering students every year. Can we use these students to create documents? We need documents, we are short of documents, unfortunately students do not like documentation even if they are good in coding. So, how do we solve this problem? We have lots of students who can do coding, but we want documentation. So, we decided to address this by solving the inverse problem. What is the inverse problem? Ask the students to write code for existing documents. For students, of course, textbooks are the best documents. So, we said ask them to write Sylab code for solved examples of standard textbooks. Notice this solved examples, we are not talking about unsolved problems. Solved examples, good textbooks give every step, step by step explanation and solution. One can implement it in Sylab and verify the Sylab code line by line and any good student should be able to contribute. So, this is how we started. If they do it for all solved examples of a book, you get one textbook companion and we pay rupees, 12,000 rupees for one textbook companion. As Honduriam, we also give certificate, we also give a link for it. As a matter of fact, there is one student from IIT Madras. He wrote to us saying that thanks to this textbook companion, he got an internship in a Japanese company. So, he was very happy about it. So, the funding for this comes from the funds, the grant that we received from the National Mission on Education through ICT, M.H.R.D., which has been very generous in supporting this activity. So, I would like to invite all students to benefit by this, to contribute to this and also to use this. How does one use it? I am going to explain it shortly. 1000 college students and faculty contributed. These students came from all over India, all parts of India, 600 textbooks were covered and 70,000 examples were coded. If you assume that there are 100 examples in a textbook, then there will be 60,000. Some textbooks have actually more than 100 examples. So, we have 70,000 examples coded. You can download these textbook companions for offline use. So, let me click this. So, this is sylab.in on the left hand side. So, this is the website that we have created and we support at IIT Bombay. By the way, the software sylab is not created by us. Sylab is, in fact, we have given a disclaimer also that it is, of course, we have said that it is a trademark of Inria and sylab enterprises and it has been now bought over by a company. And I will show the link for that here, but let us come here, let us come back to this page and let us go to textbook companion project and you have something called completed books. When we click this, you can see that there are 594 books that have been completed. So, it has, if I just scroll down, you will see that there are indeed 594 books. Here it is. It is possible to get books according to specialization. So, let me do that. Instead of choosing all categories, let me choose electrical engineering, for example. And in that, let me choose, there are more here. Signal processing. Now, if you go through this, you see that in signal processing alone, there are 17 books. So, this is a very popular book, Prokis and Vanillakis, DSP. So, let me click this and it says that download codes. Notice that we are not giving a book, we are only giving sylab code. To understand that code, you need the book. As a result, this is a true textbook companion. It only gives the sylab code, it does not give the book. We cannot copy the book and distribute. That will be a violation of copyright. We do not do such illegal things. So, here if you click this, you can download the entire sylab code. If you click here, you can get the PDF. Let us click this and see what it has. So, it is downloaded here. So, here you are. This is created by Professor Senthil Kumar from IRTT in E-Route. He is a college teacher and let us go down. So, it has all the examples by chapter. You also have it in terms of example number. So, for example, if you want to say exponential decreasing signal, example 2.1.09, let me click this. There it is. Example 2.1.09. So, you can reach this directly and notice that it has code after code after code which is not given in the book. What is given in the book is not reproduced here. As a result, there is no copyright violation at all. As a matter of fact, it is the other way around. We are helping authors of books by giving sylab code. There may be authors who may not have given any code with their book, but we have given sylab code and we have given it for 600, close to 600 books, in fact, 594 as of now and there are some more books in pipeline. Those are undergoing reviews, revision and so on and so forth. Let me just see. We have anything else here? We can download the code for an entire book or a chapter. Let me show you. So, here I showed how to download a PDF version. Let me close this. We are back in the download course that we saw earlier. So, instead of download PDF, if you download here, you will get all the sylab code as a zip file. Instead, you can say that let us open discrete time signals and systems. Chapter 2, let us choose an example. Let us say exponential increasing, decreasing signal. Here is the code. So, I do not have to download the entire book. I have I can choose a chapter. If I click here and download, I will get the zip file for that chapter only. Instead, I can say that I do not want it for the whole chapter. There are too many things. I get confused. I want sylab code for only one example. So, I have selected this. So, let me click this, let me show in finder. I ran it. You see the output. So, it is possible to do that. Let me close this. So, as I told you earlier, you can download the code for an entire book or a chapter or an example. So, which is very useful because you can just go to the example that you like, download only that code, run it and test it. Now, I am going to give a demo of sylab cloud on Garuda. So, here is the link. Let me click this. So, let me demonstrate it. Let me choose once again electrical engineering. I will choose control systems. I will choose VCCO, frequency domain analysis. See how it is organized. First, the main category, then subcategory in that what is the name of the book and what is the chapter and what is the example. So, let me select that example. I want to choose body plot. The moment I select it, I get the code here. So, this is written by some student, one of your friends from across the country. So, let us execute this. So, it gives the body plot. You can download it if you want. Let us close it and here is the result. Let me zoom it a little bit. You can actually see that. Now, I am going to ask you a quiz. Suppose I increase the gain of this transfer function, let us go to 5000, that is right. You can actually edit this page. So, I have changed this from 2500 to 5000. Now, if I do that, what will happen to gain margin and face margin? I want you to note down. Gain margin is 14, face margin is 31. If I increase the gain, what will happen for this system? Let us go ahead. So, this goes to Garuda Cloud, which is hosted in Bangalore by CDAC. Let me close this. Yes, if you guessed it correct, the margins will come down, 14 has become 8 and 31 has become 17. So, it is possible for you to try out all the 70,000 examples on the cloud. So, how do we use this TBC as a documentation? What do I mean by that? Supposing you want to know how to use Sylab for fast Fourier transform, because you have it in your course. So, open the textbook and there must be an example that shows how to solve fast Fourier transform, how to implement fast Fourier transform. So, that example is given. You go to the textbook companion in Sylab. As 600 books are covered, most likely your textbook also is covered. You go to that chapter, that particular example and open the Sylab code. It tells you how fast Fourier transform is done. What do we do? If your book is not covered, you propose. You propose that you ask a smart classmate in your class to do this for you and that person can create a textbook companion on that book and the problem is solved. It can be used as a documentation as I mentioned. It can be used for what-if studies, like I mentioned for example, like we did for example, increase the gain by 2. You may want to reduce the friction factor by 10. You may want to change the bandwidth of some communication channel and so on and so forth. So, it is very easy. If you are a faculty member, you are teaching the class, just project this and then you can just do this online. Of course, you need internet connection. If you do not have internet connection, use the offline version that I showed you little while ago. It is of course, useful for students also. You want to understand how a particular topic is covered. You want to improve it. So, you can do that. As a matter of fact, I believe that this alone, that is the textbook companion alone is useful to most of the 40 lakh engineering students who are in our colleges at any time. So, for them, Sylab is more than enough. It is only for a very small fraction of the students who may want some extra things which may not be available in Sylab. They might say they want to use some other software. My question to you is, so, for that 1 percent of the students, should you use some other software that will tax all the 99 percent of the students? That is why I say that use Sylab wherever possible and that Sylab is good enough for the 99 percent of the students like we demonstrated. For the remaining 1 percent of the applications, use whatever software, whether it is open source or commercial, whatever it is, but do not impose that commercial software on the 99 percent of the students who can get by with Sylab. It is also true for industry. How many companies solve earth-shattering problems all the time? Very rarely do they solve such problems. For most of them, what is available in Sylab is more than enough and it is absolutely open source. All companies can also use Sylab absolutely free of cost. And of course, this is useful to people all over the world. Imagine this is something created by us, by our students, by who are funded by our taxpayers made available to the whole world and that is the beauty of open source software. You create a good product and share it and lots of people can benefit by that. Just like Sylab was created by somebody and they left it as open source for all our students to benefit, we also reciprocate in this manner. There is another very nice thing that we have created on top of this textbook companion, code search. Let me show you. Let me click this link. If you click this, it comes here, once again it is in sylab.in website. How did I reach here? Search TBC code search, this is what I find. So, how do I use it? Well, you need to know the name of the command. How do I locate the name of the command? I do a Google search. For example, I wanted to set a problem in partial fraction in Sylab. I had forgotten the command. I had forgotten the syntax. So, I said partial fraction Sylab. So, the very first link is PFSS. So, I know the command name. I found the command name. Now, how do I find examples? I have had many bad experiences of trying to get a working example in the past. And I do a Google search. I get lots of hits, 100,000 hits, but not a useful one. I had to really search one after another to find a working code. But we have solved the problem in our code search here. Remember, the command is PFSS. So, I come here and I search PFSS and I search. It says 140 results found. Where are these from? Remember, I told you that there are 70,000 examples that have been coded by your classmates, students across the country. They have made available, out of the 70,000 examples, 140 of them have used PFSS. The first one is by this circuit analysis book. So, let me go down. Here is a book by Ashok. Here is a book by Babu. Here is a book by Salivahanan. Here is a book by Manke. You keep doing it until you like a book that is displayed. Here is the book by Kofner, which I used when I was a student. I said, hey, you know, I have used this book. Let me view this example. It immediately takes me to the Sylab on cloud that we have seen before. This is example 4.2 in that book. And if you see here, notice that PFSS is here. So, all I have to do is to execute and I get the result. Only the denominator is displayed. That is because after numerator, there is a semicolon. Let me delete it, let me run it and I get numerator also displayed. You can see that partial fraction is with the denominator s minus 2. This is s plus 1, s minus 1 and so on. So, if I do not like this, I can modify it, rerun it, I get an example and so on. So, this is extremely useful for faculty members. If they want to set problems for lab exam, final exam, whatever it is. And you can do this for all kinds of applications. Of course, it will also help you to identify examples for the command that you want to find out.