Difference between revisions of "Template"

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(Converted to new hexboard diagrams)
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A '''template''' is a [[pattern]] which guarantees some kind of [[connection]]. There are several different (and sometimes overlapping) types:
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A '''template''' is a minimal [[pattern]] that guarantees some kind of [[connection]]. There are several different (and sometimes overlapping) types:
  
 
* [[:Category:Edge templates |Edge templates]]
 
* [[:Category:Edge templates |Edge templates]]
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* [[Second order template]]s
 
* [[Second order template]]s
  
The '''carrier''' of a template consists of all of those cells (occupied or empty) that are part of the template. Empty cells in a template's carrier are an important part of the template and must not be ignored: if any of these cells are occupied by the opponent, the template is typically no longer valid.
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== Carrier ==
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The '''carrier''' of a template consists of all of those cells (occupied or empty) that are part of the template. Empty cells in a template's carrier are an important part of the template and must not be ignored. If any of these cells are occupied by the opponent, the template is no longer valid.
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== Minimality ==
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Templates are, by definition, minimal. This means that removing any of the stones or empty hexes from the template should no longer guarantee the connection. For example, the following pattern guarantees a virtual connection of the red stones to the edge. However, it is not a template, because it is not minimal.
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<hexboard size="4x5"
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  coords="hide"
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  edges="bottom"
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  visible="area(d1,a4,e4,e1)"
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  contents="R d1 e1"
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  />
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The following pattern has a smaller carrier and guarantees the same connection. It is minimal, i.e., removing any red stone or any empty hex makes the pattern no longer connected. Therefore it is a template. It is known as [[Edge_template_IV2a|edge template IV-2-a]].
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<hexboard size="4x4"
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  coords="hide"
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  edges="bottom"
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  visible="area(c1,b2,a4,d4,d1)"
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  contents="R c1 d1"
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  />
  
 
== Overlapping templates ==
 
== Overlapping templates ==

Revision as of 00:17, 8 December 2020

A template is a minimal pattern that guarantees some kind of connection. There are several different (and sometimes overlapping) types:


Carrier

The carrier of a template consists of all of those cells (occupied or empty) that are part of the template. Empty cells in a template's carrier are an important part of the template and must not be ignored. If any of these cells are occupied by the opponent, the template is no longer valid.

Minimality

Templates are, by definition, minimal. This means that removing any of the stones or empty hexes from the template should no longer guarantee the connection. For example, the following pattern guarantees a virtual connection of the red stones to the edge. However, it is not a template, because it is not minimal.

The following pattern has a smaller carrier and guarantees the same connection. It is minimal, i.e., removing any red stone or any empty hex makes the pattern no longer connected. Therefore it is a template. It is known as edge template IV-2-a.

Overlapping templates

Two templates overlap if some empty cell belongs to both of their carriers. Care must be taken with overlapping templates: although each template may be valid individually, the overlapping templates may not form a valid connection as a whole. The simplest example is the following situation, called a U-turn:

123

Although 1 is connected to 2 via a valid bridge template, and 2 is connected to 3 via a valid bridge template, 1 is not connected to 3, because the bridges overlap at *. In fact, if Blue plays at *, Red cannot defend both bridges in a single move.

See also

Reference