Fluid flows. Now, this is what we'll be discussing today. So this behavioral pattern inside the shock tube is due to the upstream flow of fluid. And it's downstream. Oh, sorry. Excuse me. So this behavioral pattern is only possible when the fluid is flowing downstream in the shock tube. Hmm. Great. Now we and Ashishapiro have to learn from an Indian rookie. And your name is? So my name is Nambi Nadinen. So Nambi, let's say you're right. I'm only human. I can make mistakes. But are you saying Ashishapiro's textbook is inaccurate? Yes, sir. It's inaccurate. Oh, well, then. Why don't you write to Ashishapiro? Tell him to correct it. According to you. He'll be very glad to hear from you, Numbu. Okay, sir. Maybe I'll just do that. Thank you for your suggestion. It's a Nambi Nadinen. Thank you very much for your letter. You're the first one to point out the printing and syntax error in Mathurum in this version of the book. I'm surprised that it went unnoticed by the professors thus far. But all the same, I assure you it will be corrected. Thank you for pointing it out. And I wish you all the very, very well. And I wish you all of the best. Thank you very much for your letter. You're the first one to point out the printing and syntax error in Mathurum. In this version of the book. Thank you for pointing it out and I wish you all the very best in your future endeavors Mr Numbu from Astor Shippur. You have a lovely day sir.