(;
AB[sb][rb][qc][pc][pd][oc][nb][mb][nd]
AW[rc][sd][sc][re][qd][qe][pe][oe][od][nc][mc][lc][lb][jb][jc]
C[White plays.

Source:
    From the endgame volume of Gokyo Seimyo, a nearly 200 year old problem set.]
(;
W[ma]
C[Simple, obvious, and slack.];
B[ob]
C[Black simply pulls back.  White has no good follow up to reduce Black's corner.  Black can expect more than 6 points of territory.];
W[na]
C[Note that White will not want to push here.];
B[oa];W[la]
C[White ends in gote, because Black's corner is alive.]
)
    (;
    W[pa]
    C[Correct.  At first glance though, White seems to gain nothing from this standard throw-in.];
    B[pb]
    C[Black has the standard defense.];
    W[ma]
    (;
    B[ob]
    C[Now this defense comes too late.];
    W[na]
    C[Black cannot block this push.];
    B[qa];W[la];B[oa]
    C[In sente, White has reduced Black to 5 points.]
    )
        (;
        B[oa]
        TR[pa]
        C[Black lives in the corner, but has an unpaid liability.  Eventually, because of the liberty shortage, Black must lose another point capturing the marked stone.];
        W[la]
        LB[na:A]
        C[This descent will be White's privilege, after which White has A.  Black's corner result is something less than 6 points.]
        )
        (;
        B[na]
        C[Too greedy.];
        W[ob]
        C[After White's throw-in snapback, Black collapses.];
        B[oa];W[ob]
        )
    )
)

