(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play and kill]AW[nl][ol][pl][rl][sl][nm][pm][qm][sm][nn][on][rn][qp][rp][rq]AB[nk][ok][pk][qk][rk][sk][ml][ql][mm][mn][pn][qn][mo][po][np][pp][pq][qq][rr][sr]
(;B[ro]C[The wedge is often the tesuji.]
;W[qo]C[It might look like white can atari and capturing the stone]
;B[so]C[However black descends and white cannot atari either side without putting themself into self-atari/])
(;B[sp]C[This move sometimes works.]
;W[ro]
;B[so]
;W[sq]C[But white easily make a second eye.]))
