127.0.0.1: Created page with "'''Color Trap''' is a type of coloring that uses a single cluster with only 2 colors to perform eliminations outside this cluster. Together with the Color Wrap, th..."

2021-10-25T12:59:09Z

Created page with "'''Color Trap''' is a type of coloring that uses a single cluster with only 2 colors to perform eliminations outside this cluster. Together with the Color Wrap, th..."

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'''Color Trap''' is a type of [[coloring]] that uses a single [[cluster]] with only 2 colors to perform eliminations outside this cluster. Together with the [[Color Wrap]], this technique belongs to the [[Simple Colors]].

== How it works ==
The following example demonstrates the principle:

[[Image:Color-trap.png]]

All the [[candidate]]s for [[digit]] '''3''' are highlighted. When a [[row]], [[column]] or [[box]] contains only 2 candidates for a digit, one of them must be true and the other must be false. These candidates have a [[strong link]]. In coloring terminology, these candidates form a [[conjugate pair]]. We can use colors to help us remember which candidates must be true or false simultaneously. In the example, green and blue colors have been applied. Notice that row 9, column 9 and box 9 all have 2 candidates for digit '''3''', which now have opposite colors.

Now either ''all'' blue cells must contain digit '''3''' or ''all'' green cells. There is no middle ground in which some blue cells and some green cells contain digit '''3'''.

Cell '''r2c6''' can [[see]] both colors. It cannot sustain a candidate for digit '''3'''.
[[Category:Solving Techniques]]

Color Trap - Revision history

127.0.0.1: Created page with "'''Color Trap''' is a type of coloring that uses a single cluster with only 2 colors to perform eliminations outside this cluster. Together with the Color Wrap, th..."