(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]RU[Japanese]SZ[19]KM[6.50]PW[White]PB[Black](;B[aa]C[Edge capture set 1];AE[aa]AW[cb][dc][qc][dd][od][pd][qe][rf][rg][qh][di][cj][dj][bk][rm][qn][po][gp][pp][gq][nq][pq][er][fr]AB[db][ec][fd][ne][oe][pe][qf][qg][ch][dh][rh][ci][bj][ck][rn][qo][qp][eq][fq][qq][gr][hr][qr]LB[cb:2][db:1][qh:1][rm:2][rn:1]C[Black to play.])(;B[ba]C[Edge capture set 2];AE[ba]AW[ib][lb][qb][jc][kc][mc][qc][bd][qd][ce][de][re][df][qf][dg][pm][qn][do][eo][dp][qp][cq][qq][cr][rr]AB[jb][kb][ic][pc][ad][id][pd][rd][be][pe][qe][cf][of][cg][ch][pl][ql][fo][ep][gp][dq][pq][dr][or][qr][rs]LB[ic:1][ad:3][bd:2][rd:1][be:1][rr:2][rs:1]C[White to play.])(;B[ca]C[Edge capture set 3];AE[ca]AW[eb][fb][dc][gc][rc][cd][gd][rd][qe][pf][dg][qg][dh][di][bj][dj][pj][rj][dk][pk][ql][qm][pn][kp][lp][mp][bq][cq][eq][fq][jq][mq][dr][fr][nr]AB[gb][pb][rb][fc][jc][qc][fd][qd][fe][pe][gf][ch][ci][bk][cl][pl][pm][rm][qn][bp][cp][dp][ep][np][dq][kq][lq][nq][er][mr][or]LB[gc:1][bj:1][qm:1][pn:3][qn:2][jq:1]C[Black to play.])(;B[ab]C[Ladders set 1];AE[ab]AW[pb][rb][fc][gc][oc][qc][dd][ed][ge][cl][el][cm][dn][do][po][ep][fp][op][gq][hq][iq][jq][oq][pq][qr]AB[qb][dc][ec][pc][cd][fd][pd][cn][co][oo][dp][gp][hp][pp][qp][dq][eq][fq]C[Black to play.For ladders that extend into the center of the board, assume that they work (ignore the stones for the other problems).])(;B[bb]C[Ladders set 2];AE[bb]AW[dc][ec][pc][qc][rc][ed][rd][ee][qe][cf][df][qf][ji][jj][jk][pm][pn][qo][dp][qp][eq][fq][hq][gr]AB[ob][pb][oc][bd][dd][hd][pd][qd][de][fe][re][bf][ef][rf][cg][dg][rg][pk][ql][dm][qn][rn][po][ro][ep][bq][dq][lq][dr][er][fr]LB[od:A][ff:A][eo:A][oo:A]TR[fe]C[White to play.In each case, does the ladder starting with A work?])(;B[ac]C[Nets and non-edge captures set 1];AE[ac]AW[eb][qb][cc][dc][qc][cd][ed][nd][pd][rd][re][ei][qi][rj][dk][rk][cl][ql][bm][dm][qm][dn][qn][ro][cp][jp][kp][qp][gq][hq][iq][lq][nq][gr][mr]AB[ec][fc][oc][pc][dd][qd][de][qe][qf][fk][qk][dl][el][pl][rl][cm][rm][rn][ho][qo][ip][jq][kq][hr][ir][lr]LB[bm:1][lr:1][mr:2]C[Black to play.])(;B[bc]C[Nets and non-edge captures set 2.];AE[bc]AW[pb][fc][gc][ic][nc][oc][pc][ed][qd][ee][qe][re][ef][gf][pf][rf][pg][rg][cl][pl][dm][pm][dn][qn][do][qo][ep][mp][pp][qp][eq][nq][oq]AB[ra][db][fb][qb][sb][ec][lc][mc][qc][rc][dd][nd][pd][rd][pe][df][qf][eg][fg][ng][qg][dh][qh][hm][om][nn][pn][eo][ho][po][cp][dp][np][op][hq][lq][mq][pq][br][dr][pr]C[White to play.])(;B[ad]C[Endgame tactics set 1];AE[ad]AW[ca][ia][db][hb][nb][bc][dc][hc][dd][hd][jd][ld][rd][be][de][he][qe][ef][pf][dh][eh][nh][oh][sh][ai][pi][qi][ri][bj][cj][dj][ej][bm][dm][qm][rm][en][on][pn][sn][eo][no][qo][cp][ep][np][pp][eq][nq][br][er][nr][rr][ds][os]AB[da][ea][ga][ha][eb][gb][ec][gc][ed][gd][fe][ff][fg][fh][fi][oi][si][aj][fj][mj][oj][pj][qj][rj][sj][ak][bk][ck][dk][ek][fk][pl][ql][rl][sl][nm][pm][sm][fp][hp][kp][mp][fq][mq][fr][mr][es][fs][ms][ns]LB[ca:2][da:1][ea:3][ga:3][ha:1][ia:2][sh:2][ai:2][si:1][aj:1][sj:3][ak:3][sl:3][sm:1][sn:2][ds:2][es:1][fs:3][ms:3][ns:1][os:2]C[White to play.In each case, does white need to protect?(Although these are separate problems, consider all white stones if they could affect either problem)])(;B[bd]C[Endgame tactics set 2];AE[bd]AW[ia][hb][sb][fc][hc][rc][cd][gd][id][qd][rd][ge][pe][gf][of][qf][bh][ch][dh][eh][fh][bi][ni][pi][qi][ri][aj][pj][sj][hp][ip][kp][mp][op][gq][mq][fr][gr][mr][nr][es][os]AB[ib][rb][ic][lc][nc][pc][qc][hd][jd][pd][he][ne][oe][hf][kf][hg][ci][di][ei][fi][gi][bj][qj][rj][dk][ok][pk][cl][qm][go][no][oo][cp][ep][gp][np][pp][rp][fq][nq][er][or]LB[ia:1][sb:1][aj:1][sj:1][es:1][os:1]C[Black to play.In each case, can black block or should black back down?])(;B[cd]C[Endgame tactics set 3];AE[cd]AW[la][jb][kb][cc][gc][ic][qc][id][rd][ce][de][re][se][af][bf][df][rf][bg][pg][qg][qi][an][rn][ao][bo][co][qo][so][dp][pp][dq][fq][gq][oq][qq][br][er][gr][or][fs]AB[lb][qb][rb][jc][kc][lc][nc][rc][qd][sd][oe][qe][cf][qf][ag][cg][dg][eg][bh][ch][bl][am][qm][rm][bn][cn][dn][qn][do][oo][po][ep][fp][gp][mp][op][eq][nq]LB[la:1][sd:1][se:2][af:2][ag:1]C[Black to play.])(;B[ae]C[Bridging under and throwing in set 1];AE[ae]AW[ca][db][qb][rb][bc][cc][ec][gc][qc][cd][kd][qd][ce][me][qe][re][of][pf][qf][qg][bj][cj][qj][ck][nk][ok][pk][qk][dl][ql][rl][bm][cm][dm][qm][nn][qn][do][qo][ro][gp][np][bq][dq][eq][fq][gq][lq][mq][nq][oq][pq][qq][rq][cr][gr][nr][rr]AB[bb][cb][sb][rc][bd][rd][be][cf][df][rf][ng][og][pg][rg][qh][bi][ci][di][qi][ri][mj][nj][oj][pj][rj][bk][rk][bl][cl][rm][hn][rn][fo][go][so][fp][hp][kp][lp][mp][hq][kq][dr][er][fr][hr][lr][mr][or][pr][qr]LB[ac:A][se:A][aj:A][sl:A][gs:A][ns:A]C[Black to play.In each case, does A save the black stones?])(;B[da]C[Edge capture set 4];AE[da]AW[cd][dd][de][cf][of][qf][pg][qh][qi][rn][po][qo][cp][ep][fp][pp][dq][gq][pq][dr]AB[nc][pc][qd][be][ce][ee][df][dg][qg][rg][ch][oh][ph][cm][rm][qn][do][ro][bp][dp][qp][cq][eq][qq][er]C[White to play,]))