(;
AB[pn][qn][rn][po][ro][so][np][op][kq][lq][mq][pq][kr]
AW[qo][qp][qq][pp][rp][sp][nq][oq][lr][mr]
C[Black plays.]
(;
B[or]
C[Mistake.];
W[nr]
C[White can simply block here.];
B[pr];W[qr]
C[White has no liberty shortages.  Black has nothing.]
)
    (;
    B[pr]
    C[At 1st glance, this move doesn't seem any better.  White still seems to have enough liberties on both sides.];
    W[or];B[os];W[nr];B[qr];W[rr];B[sq];W[rq];B[rs];W[sr]
    C[White has enough liberties on the right to survive, but ...];
    B[ls]
    C[... Black can hane here to protect liberties that White needs to atari the inside stones.  And so White is powerless to stop Black A.]
    LB[ms:A]
    )
)

