(;GM[1]FF[4]SZ[19]
GN[White ko threat executed]
PC[http://senseis.xmp.net/?KoExchange]AP[GoWiki:2009]
DT[2013-01-10]
C[Diagram from http://senseis.xmp.net/?KoExchange

White ko threat executed]
PL[B]

AB[aa][ba][ca][fa][bb][gb][bc][cc][gc][mc][nc][oc][ad][cd][ed][fd][gd][ld][pd][rd][de][ee][ie][ke][le][me][re][df][ef][jf][mf][rf][dg][jg][kg][lg][og][pg][qg][eh][fh][gh][nh][rh][bi][ci][di][ji][ki][ni][ej][fj][gj][hj][ij][jj][nj][hk][mk][nk][ok][fl][ml][ol][ql][qo][qp][cq][fq][oq][dr]
AW[da][ea][cb][eb][ac][dc][ec][fc][kc][lc][bd][dd][hd][jd][kd][md][nd][od][be][ce][he][je][cf][ff][hf][if][lf][nf][of][pf][qf][cg][eg][fg][mg][ng][rg][bh][ch][dh][hh][ih][lh][mh][oh][ei][fi][gi][hi][mi][kj][mj][pj][bk][ck][dk][fk][gk][ik][jk][lk][gl][hl][ll][nl][mm][nm][cn][dp][rp]
CR[cb]

;B[db]C[B1]MN[1]
;W[qh]C[W2]MN[2]
;B[fb]C[B3]MN[3]
;W[sg]C[W4]MN[4]

;CR[cb]
)
