Gokyo Shumyo, Section 6, Problem 21 / Attempts

 

2 here is the solution. Black connects and saves:

 

Or black defends his weakness:

ChrisSchack: Nothing prevents B from defending at the circled point. was captured. If I knew how.

Related connection problem  

unkx80: I strongly suspect that this Gokyo Shumyo problem may be solved using ideas from the connection problem on the left.

Actually, I am very sure that the connection problem on the left can be found somewhere on SL...

White to play and connect underneath - II (Ko, best for black?)  

Tapir, can't W just fill at with to avoid the ko? That leaves and a as miai to connect.

Tapir: Oh my god! Sure...