169.231.6.12: me responding to "Is it a seki"? regarding case (a) (2018-09-06 23:42) [#11175]

I have not ruled out the possibility that at least one player will be independently alive.

Assuming that doesn't happen, case (a) is no worse for White than seki, and excludes cases in which Black has a non-removable ko threat that is not loss-making by the entire corner. (Examples of positions where the defender does have such threats: these situations?, double-ko sekis, and sending 2 returning 1.)

I use case (a) to avoid issues regarding how exactly seki is defined, and show that

• I don't need to count 2-stone position in sending 3 returning 1 as good-enough for White, and

• for the purpose of White doing well-enough, I don't need to consider Black as having done well-enough in the corner of self-contained Moonshine Life

.

(I still need to consider Black's self-contained Moonshine Life corner as not killable to be sure of my conclusion that after , White is still not threatening a ko to kill Black.)