Problem diagram.
Black plays in the upper right.

Source:
American Go Journal, Vol. 19, No. 4, 1985, p. 27
"Guerilla Tactics for Beginners , by Cho Chi Kun 9 dan

Solution follows    (or click here to download SGF)

Correct.
Black 1 is quite an effective move that fully uses the aji of Black's captured stone. If White simply captures with 2, Black pulls back with 3. All of Black's stones are working efficiently together.

White variation.
White 2 is inferior. Black forces with 3 and then capturing a stone with 5 to unite Black's stones is a great success for Black. White can capture the Black stone on the side, but Black would block, with the result that White would only gain a small endgame play in gote.

White variation.
White can also resist by pushing into the corner with 2. White must fully commit to the corner with 6, but Black can escape down the side with 9. With 11, Black sacrifices the corner stones.

This entire sequence is very instructive. Black has given up 4 corner stones, but has nice outside influence, while White's 3 side stones have limited prospects. Black is more than satisfied.

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