(;GM[1] FF[4] AP[Hibiscus:2.1] SZ[19] ST[3] SO[Old Chinese tsume-go book] US[Merlijn Kuin] GC[Difficulty: 100/100] ;C[One of the most difficult to find, as well as one of the most beautiful tesuji I've ever seen: Somehow black has to save both his groups.] N[Problem 1] AB[dd][eb][fd][fe][gf][ha][hb][hc][hd][hf][ic][ie][jb][je][kd][ke][ld][lf][me][od][pc] AW[gb][gc][gd][ge][he][ib][id][if][jc][jd][jf][kc][kf][lc][mc][mf][nc][nf][ob] ;B[nb] C[O.k. now you know this move, but how should white answer it?] N[Problem 2] (;W[na] LB[na:2][ne:A][lg:B][ga:C][na:2][nd:D]C[The correct move.] (;B[ga] ;W[md] ;B[le] ;W[lg] ;B[ne] ;W[oe] ;B[nd] ;W[pd] ;B[oc] ;W[qc] ;B[pb] ;W[pa] C[White is trapped in ko. Very nice isn´t it. RIGHT] )(;B[nd] ;W[ja] C[Black is captured.] )(;B[ne] ;W[ja] C[Black is captured.] )(;B[lg] ;W[ja] C[Black is captured.] ))(;W[oc] ;B[ne] ;W[ga] ;B[ia] ;W[ka] ;B[kb] ;W[la] ;B[lb] ;W[ma] ;B[mb] ;W[na] ;B[fc] )(;W[mb] ;B[ga] ;W[md] ;B[le] ;W[lg] ;B[ne] ;W[oe] ;B[nd] ;W[pd] ;B[oc] ;W[qc] ;B[pb] )(;W[oa] C[A tricky response: black has to be on his guard. Any idea for the next move?] N[Problem 3] (;B[na] C[Tesuji number 3.] ;W[ka] ;B[kb] ;W[la] ;B[lb] ;W[ma] ;B[ga] )(;B[oc] C[Looks nice but white has a counter:] ;W[ja] ;B[ia] C[If black extends white captures him in a snap-back.] ;W[ka] C[black is dead.] )))