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Talk:Sashimi Swordfish
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Ruud, Your both your examples are solved very quickly using simple colouring through hinges (weak colouring). I don't know how general this will be but I suspect that it would take a fairly fully populated example with no conjugate pairs anywhere, to require the full Sashimi treatment.
David 12:16am GMT 26/11/06
David,
Sashimi Fish are "skinny" by definition, making it impossible to find one without conjugate pairs. There is always a considerable overlap in the single-digit techniques. These 2 examples are quite rare. In my database with millions of Sudokus, there are only a handful that can be solved with singles and a Sashimi Swordfish.
--Ruud 02:11, 26 November 2006 (CET)
There is an inconsistency here. The sentence under the "Sashimi Swordfish in the Columns" figure reads:
This diagram shows that each defining column can have 2 or 3 candidates, and the defining columns that intersect the extra box can have only a single candidate that belongs to the underlying Swordfish.
By symmetry, for the "Sashimi Swordfish in the Rows" figure we should expect that "the defining row that intersects the extra box can have only a single candidate that belongs to the underlying swordfish." However, there are two such candidates in that figure. (Also, there are no conjugate pairs.) I do agree that the eliminations shown are valid. It may be just a matter of semantics whether you want to call patterns such as this "sashimi" fish, but you can cover eliminations from patterns such as this, and truly "skinny" sashimi patterns, with the same logic. Just mentally place hypothetical candidate(s) in the missing vertex or vertices of the fish which lie in the box, converting the pattern into a finned fish. Any eliminations from the finned fish are also valid eliminations from the original pattern. (The fact that we happen to know some of the candidates in the finned fish are false does not invalidate the logic behind finned fish eliminations.)
--Rmoore 00:31, 19 July 2007 (CEST)
