(;AB[ar]AB[bq]AB[bo]AB[cp]AB[do]AB[fo]AB[fp]AB[hp]AB[hq]AB[hr]AB[jr]AW[br]AW[bs]AB[cr]AW[cq]AW[dq]AW[eq]AW[gq]AW[gr]AP[goproblems] (;W[ds] (;B[gs]C[CHOICE] (;W[fs];B[fr] (;W[fq];B[es];W[er]C[RIGHT]) (;W[hs];B[fq]) (;W[er];B[fq]) (;W[es];B[fq])) (;W[dr];B[fq]) (;W[fr];B[fs] (;W[es];B[hs]TR[dr]TR[fq]C[White is dead.]) (;W[dr];B[fq]) (;W[fq];B[es])) (;W[fq];B[fs]) (;W[hs];B[fs]) (;W[er];B[fs])) (;B[fr]C[CHOICE] (;W[fq];B[gs] (;W[fs];B[es] (;W[er]C[RIGHT]) (;W[dr];B[hs])) (;W[er];B[fs]) (;W[cs];B[fs]) (;W[es];B[fs]) (;W[dr];B[fs])) (;W[dr];B[fq]) (;W[er];B[fq]) (;W[gs];B[fq]) (;W[fs];B[fq]))) (;W[dr];B[fr] (;W[fq];B[gs] (;W[er];B[fs];W[es];B[cs]C[If White captures the triangled stones Black captures the corner stones; White has only one eye.]TR[fs]TR[fr]TR[gs]) (;W[es];B[cs]LB[ds:A]LB[fs:B]C[If White A then Black B; if White B then Black C. White has only one eye.]LB[as:C]) (;W[fs];B[es]) (;W[cs];B[es]) (;W[ds];B[fs])) (;W[er];B[fq]) (;W[es];B[fq]LB[er:B]LB[cs:A]C[White now needs both A and B to live.]) (;W[fs];B[fq]C[Dead as a dodo.]) (;W[cs];B[fq]C[A and B are miai. C doesn't even have to be answered.]LB[es:A]LB[er:B]LB[fs:C]) (;W[gs];B[fq] (;W[es]MA[er]MA[cs]C[Dead as it stands; White needs both marked points to live...]) (;W[fs]C[White has only one eye.]) (;W[cs]MA[es]MA[er]C[Dead, as White needs both marked points to live.]) (;W[ds]C[Just one eye!]) (;W[er]MA[cs]MA[es]C[Dead, as White needs both marked points to live.])) (;W[ds];B[fq])) (;W[es];B[cs]) (;W[fq];B[cs]) (;W[cs];B[fq] (;W[fr];B[dr] (;W[er];B[gs] (;W[fs];B[ds]) (;W[ds];B[fs])) (;W[gs];B[ds]) (;W[es];B[gs]) (;W[ds];B[gs];W[fs];B[er])) (;W[dr];B[fr]C[A and B are miai.]LB[er:A]LB[es:B]) (;W[er];B[fr]C[Just one eye.]) (;W[es];B[fr]C[Just one eye.])) (;W[ap];B[cs]C[White cannot save the corner stones, and throwing in fails because of damezumari.]) (;W[er];B[cs]) (;W[fr];B[cs]) (;W[fs];B[cs]) (;W[gs];B[cs]) (;W[aq];B[ap]C[Even if White proceeds to live this exchange has wasted a ko threat for no gain at all]) (;W[bp];B[ap]C[White can still live, but this exchange just wastes a ko threat for no gain.]) (;W[ep];B[cs]C[White may cut Black, but cannot escape, nor live, nor catch Black's surrounding group(s).]) (;W[en];B[cs]C[White may cut Black, but cannot escape, nor live, nor catch Black's surrounding group(s).]) (;W[ho];B[cs]C[White may cut Black, but cannot escape, nor live, nor catch Black's surrounding group(s).]) (;W[co];B[cn]C[Although White can still live, this exchange only strengthened Black's outer position for no gain.]) (;W[ao];B[cs]) (;W[dp];B[cs]) (;W[eo];B[cs]) (;W[gp];B[go]C[];W[ds];B[gs];W[fs];B[er] (;W[dr];B[fq]) (;W[fr];B[dr])))