Easy life-and-death problem that came up in a game I played.
(;GM[1]FF[4]AP[glGo:1.3.1]ST[1]
SZ[19]KM[6.5]
PW[White]PB[Black]
AB[ie][jf][je][jd][kf][ke][kd][ma][lb][lc][ld][mc][nd][oe][od][pa][pc][pd][qb][qa]AW[pe][pf][qf][rb][ra][mg][lg][kg][jg][if][hf][he][hd][id][ib][jc][kc][kb][ka][la][me][of][ne][qd][qc]C[White to kill. This position came up in the endgame (I was white, six-stone handicap). I had just cut off Black from a strong group on the left side.
Any corrections / comments are welcome.]
(;W[ob]
;B[nb]
(;W[pb]
(;B[oc]
;W[oa]LB[md:B][na:A]C[A and B are miai for the kill.RIGHT])
(;B[md]
;W[oa]LB[oc:B][na:A]C[A and B are miai for the kill.RIGHT]))
(;W[oa]
;B[pb]C[The almost fill does not work - Black has two eyes.])
(;W[oc]
;B[pb]C[The almost fill does not work - Black has two eyes.]))
(;W[nb]
;B[ob]
(;W[mb]
;B[nc]
;W[na]
;B[oa]C[This is even worse than failing, as White must play at A to protect her three stones.])
(;W[na]
;B[nc]
;W[mb]
;B[oa]LB[ma:A]C[This is even worse than failing, as White must play at A to protect her three stones.]))
(;W[md]
(;B[ob]
;W[nb]
;B[mb]
;W[nc]
;B[oc])
(;B[nb]
;W[ob]
;B[pb])))
