The white stone captured by 3 only makes a false eye.
White makes a four-point nakade. Black is dead.
mgoetze: Since this is not on the solution page it must be a failure... could someone show me the refutation please? :(
Gorobei: this looks bad.
tapir: Hm, am I missing sth or is Black alive after at a? I am missing sth.
unkx80: How about this?