: ( 172)
If White connects below, Black simply captures at . Thereafter, 76 and 77 are miai for two Black eyes. The left side of the board is yet untouched, so White has no chance of winning.

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:
If Black has played the guzumi exchange earlier (or plays it now, with , , for demonstrative purposes), he would continue with a move at , as usual. Again, Black's group in the top right has 13 liberties left (), sufficient to get the same result as with our solution.