(;AW[cp]AW[bp]AW[dp]AW[ep]AW[fp]AW[gp]AW[gq]AW[gr]AB[hr]AB[hq]AB[hp]AB[go]AB[fo]AB[eo]AB[do]AB[co]AB[bo]AB[ho]AB[gs]AW[fs]AB[hs]AW[br]C[tenuki=T]LB[cn:T]AP[goproblems]
(;B[cn]C[Black can make big inroads into the white territory.])
(;B[fr]
(;W[es];B[er];W[ds]
(;B[cr];W[cs]
(;B[bs];W[as];B[dr];W[cq]
(;B[bs];W[cs]
(;B[aq]C[corecct!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!RIGHT])
(;B[ds];W[aq]
(;B[bs]C[ko])
(;B[ao];W[ap];B[bs]C[ko])
(;B[fs];W[bs]C[White lives unnecessarily.]))
(;B[ap];W[aq];B[ao]C[RIGHT]))
(;B[aq]C[];W[bq]
(;B[bs]C[corecct!!!!!!!!!!!!!!!!!!!!!!!!!!!!!RIGHT])
(;B[ap];W[bs]C[White gets at least seki. Black A5 next is worth 8 points in gote.]))
(;B[ap]
(;W[aq]C[White may play like this...]
(;B[ao];W[bs])
(;B[bs];W[ao]
(;B[an];W[ap]
(;B[cs];W[bn]C[White only plays A3 in this sequence if White can capture A6. If not, White has another option.])
(;B[bn];W[cs])
(;B[bm];W[cs]))
(;B[cs];W[bn]C[White is out.])))
(;W[bs]C[Or this...]
(;B[aq];W[bq]C[White gets at least seki. Black A5 next is worth 8 points in gote.])
(;B[ao];W[aq]C[Alive.]))))
(;B[dr];W[bs]C[Black achieves nothing.]))
(;B[dr];W[cs];B[cr];W[bs]C[Black achieves nothing.])
(;B[cs];W[dr]
(;B[cr];W[dq])
(;B[dq];W[cr])))
(;W[dr]C[White would of course do better by playing like this and live in sente.RIGHT]))
(;B[ap];W[aq]C[Compared to the correct solution, black's gain is so small as to be negligible.])
(;B[er];W[fr])
(;B[es];W[fr]))