origin in Russian Epigraph: The little son came to his father and asked the little one: - That means good and what means bad? Preface: This work is not presented in the form of a lecture, but rather a summary of the lecture, a sketch, an outline. This work contains theses that should be used as hyperlinks. The information is provided in a compressed form, which requires additional time to decrypt, so I recommend reading slowly. And even better, re-read it several times, but not in a row, but after a certain period of time...

It was a pretty average day for me, Layla, your typical schoolgirl. Sitting at my computer, doing homework - that's how it went. But after a few moments when I had started my Maths tasks, I felt something appear at my window. Turned my head around to notice a portal - a real portal staring at me! And the more I looked the better I understood two things: how pathetic my magic was against this and how familiar the landscape inside of it was. An old, dark wooden corridor was staring at me. I didn't...