(;AB[br]AB[as]AW[bs]TR[ds]TR[dr]TR[dq]TR[cq]TR[bq]TR[aq]C[2x3 board. Black to win.FORCE]AP[goproblems]
(;B[cs]TR[ds]TR[dr]TR[dq]TR[cq]TR[bq]TR[aq]C[Black has three eyes.RIGHT])
(;B[cr]TR[ds]TR[dr]TR[dq]TR[cq]TR[bq]TR[aq]C[.FORCE];W[ar]TR[ds]TR[dq]TR[dr]TR[cq]TR[aq]TR[bq]LB[br:X]LB[cr:X]C[Ko. There are no ko threats. White captures the marked stones X.])
(;B[ar]TR[ds]TR[dr]TR[dq]TR[cq]TR[bq]TR[aq]AW[bq]AW[aq]C[.FORCE];W[cr]TR[ds]TR[dr]TR[dq]TR[cq]TR[bq]TR[aq]C[White wins. ]))