TwT: @caranthir: argh! I did silly things close to: before you dare to ask Master Ivan, kiss his feet. While typing the answwer below, and breathing, and smiling, not forget breathing --- there was one moment: Better let caranthir do the job? :p
moo11: So what is the move that lives after E18A18? I want to know what I'm missing.
caranthir: [TwT: I strongly support you asking for assistance in a way others could see as appropriate. Good luck with your studies!] ------ To me it certainly looks like a ko after, for instance, P2T2T1T4. (To play something else instead of taking at T1 doesn't refute the ko status). Now of course we have plenty of room to expand our group on the side (kind of local ko threats to make the group definitely live anyway) and the opponent would have to put in quite a plenty of moves in order to properly murder the group to death. To put it another way, there's no *efficient* way for the time being to threaten that group by ko. If the opponent really, really insisted on killing the group, we would get too many moves elsewhere in the meantime. That's probably the reason Ivan said "ko is not the solution" (It could be different if we imagined the rest of the board already very settled and this being endgame.)
moo11: Yeah I'm saying if E18 leads to ko it shouldn't be correct.
TwT: Dear moo11,
While I understand your perspective, it's important to note that language has historically served as a tool for humans to understand each other and minimize misunderstandings. Initially, you proposed a ko sequence. Master Ivan, with minimal effort, could likely determine that there is a solution without involving a ko. Subsequently, you concluded that E2 is incorrect. However, I would like to suggest that you reconsider the sequence E2 - A1 and evaluate whether A2 is indeed the optimal follow-up move.
You have a point. I do not like P2.