(;
AB[fq][gq][cp][dp][ep][ip][pp][bo][co][io][dn][gn][pn][ck]
AW[bq][cq][dq][eq][iq][jq][nq][bp][fp][jp][fo][cn]
C[White plays.

Source:
     Tesuji Dictionary, by Segoe Kensaku & Go Seigen]
(;
W[gp]
C[Forming the empty triangle here is the tesuji!]
(;
B[hp];W[hq];B[er]
C[Now starts a liberty race in which Black seems to have the advantage.]
(;
W[fs]
C[A very surprising tesuji!];
B[hr];W[gs]
C[White makes two edge moves in a row!  Finding a more peculiar looking tesuji sequence would be difficult.];
B[es];W[dr]
(;
B[hs];W[ds]
C[White saves his 3 stones above.]
)
    (;
    B[fr]
    C[Connecting here is no better.];
    W[ds];B[gr];W[ir];B[hs];W[is]
    C[Again White wins the semeai.]
    )
)
    (;
    W[dr]
    C[Simply blocking here doesn't work.];
    B[hr];W[gs]
    C[Now White is too late with the 1st line tesuji.];
    B[gr];W[ir];B[fs]
    C[Black wins the semeai.]
    )
    (;
    W[hr]
    C[And descending here is too slow.];
    B[fr]
    C[Black wins the semeai with 4 liberties to 3.]
    )
)
    (;
    B[hq]
    C[Increasing the group's liberties doesn't work either.];
    W[hp];B[ir];W[jr];B[er];W[dr];B[gr];W[hs];B[is];W[js];B[hr];W[fs]
    C[White captures the group.]
    )
)
    (;
    W[hq]
    C[Bad timing.];
    B[gp]
    C[Black, now without a liberty shortage, saves his own stones and cuts off White's 2 stones.]
    )
)

