(;FF[4]GM[1]CA[UTF-8]AP[besogo:0.0.2-alpha]SZ[19]ST[0]
AB[nr][oq][or][os][pq][qq][qr][rq]AW[mq][mr][ms][np][nq][ns][op][pp][ps][qp][ro][rr][rs][so]
C[W really wants to kill B]
(;W[sq]
;B[sr]
(;W[rp]
;B[sp]
C[Right, ko! RIGHT])
(;W[qs]
;B[sp]LB[pr:A][rp:1][sq:2]
C[Seki after 1-2. If W skips 1, Black can play at A.])
(;W[sp]
;B[qs]
C[B is alive thanks to the snapback!])
(;W[ss]
;B[qs]))
(;W[qs]
;B[sq]LB[rp:1][sp:3][sr:2]
C[Seki])
(;W[sr]
;B[sq]LB[qs:2][rp:1])
(;W[rp]
;B[sq]TR[qs][sr])
(;W[sp]
;B[sq]TR[qs][sr]))