127.0.0.1: Created page with "When a solving technique only deals with the candidates for a single digit, it is customary to use the letter '''X''' to replace this digit, both in chain nota..."

2021-10-24T18:51:58Z

Created page with "When a solving technique only deals with the candidates for a single digit, it is customary to use the letter '''X''' to replace this digit, both in chain nota..."

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When a [[solving technique]] only deals with the [[candidate]]s for a single [[digit]], it is customary to use the letter '''X''' to replace this digit, both in [[chain]] notation and in the illustrating diagrams. This abstraction helps the reader understand that this is a [[single-digit]] technique and focus on the [[pattern]] rather than the [[pencilmark]]ed candidates.

You are advised to use '''fish diagrams''' to illustrate these techniques. These diagrams are based on a text format used in fish-related topics in the [http://www.sudoku.com/forums/index.php Sudoku Players' forum].

Here is an example, illustrating a [[Finned Swordfish]]:

[[Image:finned swordfish.png]]

This is the same example in the text format used in the forums:

. / . | . / . | . / .
* X * | . X . | . X .
. F . | . / . | . / .
--------+---------+--------
. / . | . / . | . / .
. X . | . X . | . X .
. / . | . / . | . / .
--------+---------+--------
. / . | . / . | . / .
. X . | . X . | . X .
. / . | . / . | . / .
If you do not have the tools to create graphical fish diagrams, use the text version instead. Sooner or later, a helpful Sudopedian will replace it with a graphical version.

== Symbols ==
There are only a few symbolic characters used in '''fish diagrams'''.
; / (forward slash)
: Cells that do not contain a candidate for digit '''X'''. These cells belong to the [[defining set]].
; X
: Cells that may contain a candidate for digit '''X'''. These cells belong to both the defining set and the [[secondary set]].
; *
: Cells from which the candidates for digit '''X''' can be eliminated. These cells only belong to the secondary set.
; F
: [[Fin]] cells. These only belong to the defining set, but are limited to a single [[house]].
; . (dot)
: Irrelevant cells. These are unmarked in the graphical version of the diagram.

== See also ==
* [[Fish]]
* [[Diagrams and Notations]]

[[Category:Solving Techniques]]
[[Category:Single-Digit]]

Sudopedia:Fish diagram - Revision history

127.0.0.1: Created page with "When a solving technique only deals with the candidates for a single digit, it is customary to use the letter '''X''' to replace this digit, both in chain nota..."