i think your explanation is very clearly, easy to understand about how to solve 8 puzzle using heuristic search procedure....... just keep make a video like this ..........regard from Indonesia
At 16:28 you draw a square that was a copy of the very first trace row square on the left with h(x)=3. You have to monitor previous diagrams and do not create duplicate squares, please. If you redraw that same square again you will be back to the second trace row again and maybe get stuck in an infinite loop. If you are tracing a large problem this is difficult but for small problems like the 8 Puzzle its not difficult to scan for duplicates, less time wasted on a visual scan than in drawing and counting. You also proved that your, take the square on the left is not always true as you edited your video to correct that possible mistake of going back to the top if you would have flipped those two squares, actually the square with the 5 in the bottom right corner at 16:28 should have never been drawn. Thank you for the very good explanation on paper.