This goes to show what happens if Black plays T15 in problem 7956.
(;AB[qa]AB[qb]AB[qc]AB[pd]AB[pe]AB[qf]AB[pf]AB[pg]AW[qe]AW[qd]AW[rc]AW[rb]AW[ra]AB[se]TR[se]LB[oc:No]C[White's corner is in danger, but Black's stone at T15 looks a bit awkward. Can White save the corner? Play P17 ('No') if you think not.FORCE]AP[goproblems]
(;W[oc]AW[qa]AW[qb]AW[qc]AW[pd]AW[pe]AW[qf]AW[pf]AW[pg]AB[qe]AB[qd]AB[rc]AB[rb]AB[ra]AW[se]C[];B[rf]C[You thought the corner was dead. So the stones have been swapped and Black has just played S14. Can you kill the corner?]
(;W[rg];B[sd]
(;W[sf]
(;B[sb]
(;W[rd]C[RIGHT])
(;W[re];B[rd]))
(;B[sg]C[CHOICE]
(;W[sh];B[sb]
(;W[rd]C[RIGHT])
(;W[re];B[rd]))
(;W[re];B[rd]
(;W[sb];B[rf])
(;W[sh];B[sb])
(;W[rf];B[sb]))
(;W[rd];B[re])
(;W[sb];B[re])
(;W[sc];B[re])))
(;W[re];B[rd]
(;W[sb];B[sf])
(;W[sf];B[sb]))
(;W[rd];B[re])
(;W[sg];B[sb]
(;W[rd];B[re];W[sf];B[rd])
(;W[re];B[rd])
(;W[sf];B[rd]))
(;W[sb];B[sf])
(;W[sc];B[sb]
(;W[sf];B[rd])
(;W[rd];B[re])
(;W[re];B[rd])))
(;W[re];B[rd]
(;W[rg];B[sd]
(;W[sf];B[sb])
(;W[sb];B[sf]))
(;W[sd];B[rg]C[The corner lives and grows rapidly.])
(;W[sb];B[rg]C[The corner lives and grows like cabbage.])
(;W[sf];B[rg]C[Come on...!])
(;W[sc];B[rg]C[Alive and kicking.]))
(;W[rd];B[re]
(;W[rg];B[sd])
(;W[sd];B[rg]C[Black gains some extra points.])
(;W[sc];B[sf]
(;W[sb];B[sd])
(;W[rg];B[sd])
(;W[sd]C[Black plays elsewhere, satisfied with living in sente.]))
(;W[sf];B[rg])
(;W[sb];B[sd]))
(;W[sf];B[rg]C[This only helps Black.])
(;W[sd];B[rg]C[Black's corner grows rapidly.])
(;W[sg];B[rg]
(;W[rh];B[re]
(;W[sf];B[sd]
(;W[sh];B[sb])
(;W[qg];B[sh]))
(;W[qg];B[sd]
(;W[sf];B[sh])
(;W[sh];B[sf]))
(;W[sd];B[sf])
(;W[rd];B[sd]))
(;W[sf];B[sd]
(;W[re];B[rd]MA[sh]MA[sb]C[Either way Black lives.])
(;W[rd];B[re]MA[sh]MA[sb]C[Black lives.])
(;W[sb];B[sh]))
(;W[re];B[rd]
(;W[rh];B[sd])
(;W[sf];B[rh])
(;W[qg];B[rh]))
(;W[rd];B[re]))
(;W[sb];B[sd]
(;W[re];B[rd])
(;W[rg];B[re])
(;W[sf];B[rg])
(;W[sg];B[rg])
(;W[rd];B[re]))
(;W[sc];B[rd]
(;W[sd];B[rg])
(;W[rg];B[sf])
(;W[re];B[rg])
(;W[sf];B[rg])
(;W[sb];B[rg])
(;W[sg];B[rg])))
(;W[rf];B[rg]
(;W[sf];B[rd]C[White cannot live without the marked stones; and they remain in atari even if White connects.]TR[qe]TR[qd])
(;W[sd];B[sf]
(;W[re];B[rd])
(;W[sb];B[rd]
(;W[re];B[rd])
(;W[sg];B[re]))
(;W[rd];B[sb])
(;W[sg];B[sh]
(;W[sb];B[rd];W[re];B[rd])
(;W[re];B[rd])
(;W[rd];B[sb]))
(;W[pc];B[rd]
(;W[pb];B[re])
(;W[re];B[rd])
(;W[sg];B[re])
(;W[pa];B[re])))
(;W[re];B[sf]
(;W[sd];B[rd])
(;W[rd]C[White dies in gote.])
(;W[sb]C[White remains dead even without Black playing.]))
(;W[rd];B[sf]
(;W[sd];B[sb])
(;W[sb];B[sd])
(;W[re]C[White is dead even if Black plays elsewhere.])
(;W[pc];B[pb]
(;W[oc];B[ob]C[Black can keep on crawling until Black has enough liberties to kill the corner.White can't block; Black would cut.])
(;W[re]C[White is dead as it stands.])
(;W[sd];B[sb])
(;W[sb];B[sd])
(;W[sg];B[sh]
(;W[sd];B[sb])
(;W[sb];B[sd])
(;W[re]C[White is dead as it stands.])
(;W[oc];B[ob]C[Black can keep on crawling until Black has enough liberties to kill the corner.White can't block; Black would cut.])))
(;W[sg];B[sh]
(;W[pc];B[pb]
(;W[oc];B[ob]C[Black can keep on crawling until Black has enough liberties to kill the corner.White can't block; Black would cut.])
(;W[sd];B[sb])
(;W[sb];B[sd])
(;W[re]C[White is dead...!]))
(;W[sd];B[sb])
(;W[sb];B[sd])
(;W[re]C[White is dead as it stands.])))
(;W[sb];B[rd])
(;W[sg];B[rd])
(;W[pc];B[rd]))
(;W[re];B[rf]
(;W[sd];B[rd])
(;W[rd]C[White dies even if Black plays elsewhere.])
(;W[sb]C[White has only one eye, because Black can play either at S16 or at T16.])
(;W[sf];B[rd]))
(;W[rd];B[rf]
(;W[sd];B[sb])
(;W[sb];B[sd])
(;W[pc];B[pb]
(;W[sd];B[sb])
(;W[sb];B[sd])
(;W[oc];B[ob]C[Black can keep on crawling until Black has enough liberties to kill the corner.White can't block; Black would cut.])))
(;W[sd];B[rf]
(;W[rd];B[sb])
(;W[sb];B[rd]
(;W[re];B[rd])
(;W[sf];B[re]))
(;W[re];B[rd])
(;W[sf];B[re]
(;W[rd];B[sb])
(;W[sb];B[rd]))
(;W[pc];B[rd]
(;W[pb];B[re])
(;W[re];B[rd])
(;W[sf];B[re])))
(;W[sf];B[rd])
(;W[sb];B[rd])
(;W[sc];B[rd])
(;W[rg];B[rd])
(;W[sg];B[rd])
(;W[pc];B[rd]))