(;
AB[er][bq][cq][dq][eq][pq][fp][op][eo][em][bl][cl][dl]
AW[fr][fq][hq][kq][cp][dp][ep][qo][dn][fn][cm]
C[Black plays in the lower left.

Source:
    Tesuji Dictionary, Vol. 1, Hasami-tsuke #10];
B[en]
C[The only move if Black is going to capture something.];
W[fo]
C[And the only move if White is going to save the stones.];
B[gp];W[ho]
C[The sequence to here is forced for both sides.

Black's 2 stones only have 3 liberties, so Black must reduce White's liberties faster than that!]
(;
B[co]
C[The only move!];
W[do];B[bp];W[cn]
C[White appears to have won the semeai.  White has 3 liberties and threatens to capture a stone.

But Black has a resource!];
B[bm];W[bo];B[bn]
C[And Black catches White in a shortage of liberties.  Black wins the semeai. ]
)
    (;
    B[bp]
    C[Too slow];
    W[co]
    C[Because Black's 2 stones only have 3 liberties, Black loses the semeai.]
    )
)

