Support: Difference between revisions

m Style and clarifications
Actually, "support" is synonymous to "is a temperament of" and from here "any temperament supports JI" is self-explanatory. It seems silly to me to exclude that case
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A [[regular temperament]] is '''supported''' by an [[equal temperament]] that [[tempers out]] all of its [[comma]]s<ref>The original definition of support in this RTT sense was given by [[Gene Ward Smith]] in [https://yahootuninggroupsultimatebackup.github.io/tuning-math/topicId_13712#13967], "Suppose T is a wedgie, and v is an equal temperament val. Then v supports T if and only if T^v = 0."</ref>. The equal temperament thus '''supports''' this temperament.
A [[regular temperament]] is '''supported''' by an [[equal temperament]] that [[tempers out]] all of its [[comma]]s<ref>The original definition of support in this RTT sense was given by [[Gene Ward Smith]] in [https://yahootuninggroupsultimatebackup.github.io/tuning-math/topicId_13712#13967], "Suppose T is a wedgie, and v is an equal temperament val. Then v supports T if and only if T^v = 0."</ref>. The equal temperament thus '''supports''' this temperament, or equivalently stated, the equal temperament ''is a temperament of'' this temperament, in the same sense as a temperament is a temperament of [[just intonation]].  


For example, [[22edo]] supports [[pajara]], because pajara tempers out [[225/224]] and [[64/63]], and 22et tempers out both of those. The supporting temperament will temper out at least one additional comma; in this example, 22et tempers out [[245/243]].  
For example, [[22edo|22et]] supports [[pajara]], because pajara tempers out [[225/224]] and [[64/63]], and 22et tempers out both of those. The supporting temperament will temper out at least one additional comma; in this example, 22et tempers out [[245/243]].  


== Generalization ==
== Generalization ==


An equal temperament is the same thing as a rank-1 temperament, and the initial definition given here where the supporting temperament is rank-1 is the most common use case as of 2022. However, in general, we can say that any lower-[[nullity]] (higher-[[rank]]) temperament is supported by a higher-nullity (lower-rank) temperament if the higher-nullity temperament tempers out all the commas the lower-nullity temperament does<ref>This is an edge case, but a temperament should have at least one comma to satisfy this definition; [[JI]] may be conceptualized as a temperament where nothing is tempered out, but clearly it would be silly to say that any temperament "supports" JI.</ref><ref>Example uses of this sense can be found on the following pages: [[Subgroup Temperament Families, Relationships, and Genes #Support]], [[Meet and join #Intra-Subgroup Temperament Meet and Join]], and [[Interior product #Applications]].</ref>. Technically speaking, we would say that the lower-nullity temperament's comma space is a [[subspace]] of the higher-nullity temperament's comma space.
An equal temperament is the same thing as a rank-1 temperament, and the initial definition given here where the supporting temperament is rank-1 is the most common use case as of 2022. However, in general, we can say that any lower-[[nullity]] (higher-[[rank]]) temperament is supported by a higher-nullity (lower-rank) temperament if the higher-nullity temperament tempers out all the commas the lower-nullity temperament does<ref>As an edge case, JI is conceptualized as a temperament where nothing is tempered out, so any temperament "supports" JI; in other words, any temperament is a temperament of JI.</ref><ref>Example uses of this sense can be found on the following pages: [[Subgroup Temperament Families, Relationships, and Genes #Support]], [[Meet and join #Intra-Subgroup Temperament Meet and Join]], and [[Interior product #Applications]].</ref>. Technically speaking, we would say that the lower-nullity temperament's comma space is a [[subspace]] of the higher-nullity temperament's comma space.


An equivalent generalized definition of "support" would be to say that the lower-''rank'' temperament maps all intervals the same way as the higher-''rank'' temperament does. In this case, the technical definition would be that the lower-rank temperament's mapping-row space is a subspace of the higher-rank temperament's mapping-row space. Another way to say this is that one can find forms of the mappings for these two temperaments where the higher-rank mapping is identical to the lower-rank mapping but with additional mapping rows. To use the 22et and pajara example above, we can see that pajara has a mapping form {{ket| {{map| 12 19 28 34 }} {{map| 22 35 51 62 }} }}, which contains 22et {{map| 22 35 51 62 }} as its second row.
An equivalent generalized definition of "support" would be to say that the lower-''rank'' temperament maps all intervals the same way as the higher-''rank'' temperament does. In this case, the technical definition would be that the lower-rank temperament's mapping-row space is a subspace of the higher-rank temperament's mapping-row space. Another way to say this is that one can find forms of the mappings for these two temperaments where the higher-rank mapping is identical to the lower-rank mapping but with additional mapping rows. To use the 22et and pajara example above, we can see that pajara has a mapping form {{ket| {{map| 12 19 28 34 }} {{map| 22 35 51 62 }} }}, which contains 22et {{map| 22 35 51 62 }} as its second row.