(;AW[ab]AW[bb]AW[cb]AW[db]AW[ec]AW[fb]AB[bc]AB[bd]AB[dc]AB[dd]AB[ee]AB[fd]AB[fc]AB[gb]AB[hc]AP[goproblems]
(;B[ba];W[fa]
(;B[eb];W[ea];B[ca]C[RIGHT])
(;B[ca];W[eb];B[da]C[Black can get more than seki]))
(;B[fa];W[ea];B[eb]C[Adv. ko])
(;B[ea];W[fa];B[eb];W[da]
(;B[ba];W[eb]C[])
(;B[eb];W[ba]C[]))
(;B[eb];W[ea]C[]))