Your notation at 5:00 is throwing me off. I'm used to seeing two rows enclosed with parenthesis for permutation groups like in a previous video in this series. Also why doesn't each of the x, and inv(x) have 3 elements, you just have "(2 3)" (I would expect (1 2 3) or something like that)
I think I "decoded" your notation. If you look back to your video "Permutation Groups and Symmetric Groups", (2 3) corresponds to alpha = (1 2 3 / 1 3 2), and (1 2 3) must correspond to delta = (1 2 3 / 2 3 1). As I followed the order of the playlist, I never encountered this alternative notation. One of the challenges of teaching is putting yourself in the mind of a newbie :)
