S-expression: Difference between revisions

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; Superparticular
; Superparticular
: The interval/comma between two consecutive harmonics. See [[superparticular]].
: The interval/comma between two consecutive harmonics. See [[superparticular]].
: These are of the form (''k'' + 1)/''k''.
: These are of the form {{sfrac|''k'' + 1|''k''}}.


; Square-particular
; Square-particular
: A superparticular interval/comma whose numerator is a square number. A shorthand (nick)name for square superparticular.
: A superparticular interval/comma whose numerator is a square number. A shorthand (nick)name for square superparticular.
: These are of the form ''k''<sup>2</sup>/(''k''<sup>2</sup> - 1) = S''k''.
: These are of the form {{nowrap|{{sfrac|''k''<sup>2</sup>|''k''<sup>2</sup> 1}} {{=}} S''k''}}.


; Triangle-particular
; Triangle-particular
: A superparticular interval/comma whose numerator is a [[triangular number]]. A shorthand (nick)name for triangular superparticular. An alternative name for 1/2-square-particular.
: A superparticular interval/comma whose numerator is a [[triangular number]]. A shorthand (nick)name for triangular superparticular. An alternative name for 1/2-square-particular.
: These are of the form (''k''<sup>2</sup> + k)/(''k''<sup>2</sup> + k - 2). (This always simplifies to a superparticular.)
: These are of the form {{sfrac|''k''<sup>2</sup> + ''k''|''k''<sup>2</sup> + ''k'' − 2}}. (This always simplifies to a superparticular.)


; 1/''n''-square-particular
; 1/''n''-square-particular
: A comma which is the product of ''n'' consecutive square-particulars and which can therefore be expressed as the ratio between two superparticulars.
: A comma which is the product of ''n'' consecutive square-particulars and which can therefore be expressed as the ratio between two superparticulars.
: These are of the form S''a''*S(''a''+1)*…*S''b'' = (''a''/(''a'' - 1))/((''b'' + 1)/''b'') = ''ab''/((''a'' - 1)(''b'' + 1)).
: These are of the form {{nowrap|S''a'' * S(''a'' + 1) * … * S''b'' {{=}} {{sfrac|{{sfrac|''a''|''a'' 1}}|{{sfrac|''b'' + 1|''b''}}}}}} {{nowrap|{{=}} {{sfrac|''ab''|(''a'' 1)(''b'' + 1)}}}}.
: Replacing/substituting ''a'' with ''k'' and ''b'' with ''k'' + ''n'' - 1 gives us an equivalent expression that includes the number of square-particulars ''n'':
: Replacing/substituting ''a'' with ''k'' and ''b'' with ''k'' + ''n'' - 1 gives us an equivalent expression that includes the number of square-particulars ''n'':
: S''k''*S(''k''+1)*…*S(''k''+''n''-1) = (''k''/(''k'' - 1))/((''k'' + ''n'')/(''k'' + ''n'' - 1)) = ''k''(''k'' + ''n'' - 1)/((''k'' - 1)(''k'' + ''n''))
: {{nowrap|S''k''*S(''k'' + 1)*…*S(''k'' + ''n'' 1) {{=}} {{sfrac|{{sfrac|''k''|''k'' 1}}|{{sfrac|''k'' + ''n''|''k'' + ''n'' 1}}}}}} {{nowrap|{{=}} {{sfrac|''k''(''k'' + ''n'' 1)|(''k'' 1)(''k'' + ''n''}}}}
: For ''b'' = ''a'' + 1 these can also be called triangle-particulars, in which case they are always superparticular.
: For {{nowrap|''b'' {{=}} ''a'' + 1}} these can also be called triangle-particulars, in which case they are always superparticular.
: These have implications for whether consistency in the (''n''+''k'')=(''b''+1)-[[odd-limit]] is ''potentially'' possible in a given temperament; see the [[#Sk*S(k + 1)*…*S(k + n - 1) (1/n-square-particulars)|section on 1/n-square-particulars]].
: These have implications for whether consistency in the {{nowrap|(''n'' + ''k'') {{=}} (''b'' + 1)}}-[[odd-limit]] is ''potentially'' possible in a given temperament; see the [[#Sk*S(k + 1)*…*S(k + n - 1) (1/n-square-particulars)|section on 1/''n''-square-particulars]].


; Odd-particular
; Odd-particular
: An interval/comma between two consecutive odd harmonics. The odd analogue of superparticular.
: An interval/comma between two consecutive odd harmonics. The odd analogue of superparticular.
: These are of the form (2''k'' + 1)/(2''k'' - 1).
: These are of the form {{sfrac|2''k'' + 1|2''k'' 1}}.


; Throdd-particular
; Throdd-particular
: An interval/comma between two harmonics 3 apart which is not superparticular.
: An interval/comma between two harmonics 3 apart which is not superparticular.
: These are of the form (3''k'' + 1)/(3''k'' - 2) or (3''k'' + 2)/(3''k'' - 1).
: These are of the form {{sfrac|3''k'' + 1|3''k'' 2}} or {{sfrac|3''k'' + 2|3''k'' 1}}.


; Quodd-particular
; Quodd-particular
: An interval/comma between two harmonics 4 apart which is not superparticular or odd-particular.
: An interval/comma between two harmonics 4 apart which is not superparticular or odd-particular.
: These are of the form (4''k'' + 1)/(4''k'' - 3) or (4''k'' + 3)/(4''k'' - 1).
: These are of the form {{sfrac|4''k'' + 1|4''k'' 3}} or {{sfrac|4''k'' + 3|4''k'' 1}}.


; ''n''-odd-particular
; ''n''-odd-particular
: An interval/comma between two coprime harmonics ''n'' apart (also called as [[Delta-N ratio|delta-''n'' ratio]]). It is the generalization of superparticular, odd-particular, throdd-particular, and quodd-particular.
: An interval/comma between two coprime harmonics ''n'' apart (also called as [[Delta-N ratio|delta-''n'' ratio]]). It is the generalization of superparticular, odd-particular, throdd-particular, and quodd-particular.
: If ''n'' is a prime, an ''n''-odd-particular interval is between two harmonics ''n'' apart which is not superparticular. For example, 5-odd-particular intervals are of the form (5''k'' + 1)/(5''k'' - 4), (5''k'' + 2)/(5''k'' - 3), (5''k'' + 3)/(5''k'' - 2) or (5''k'' + 4)/(5''k'' - 1).
: If ''n'' is a prime, an ''n''-odd-particular interval is between two harmonics ''n'' apart which is not superparticular. For example, 5-odd-particular intervals are of the form {{sfrac|5''k'' + 1|5''k'' 4}}, {{sfrac|5''k'' + 2|5''k'' 3}}, {{sfrac|5''k'' + 3|5''k'' 2}}, or {{sfrac|5''k'' + 4|5''k'' 1}}.
: If ''n'' is a composite, an ''n''-odd-particular interval is between two harmonics ''n'' apart which is neither superparticular nor of ''m''-odd-particular intervals where ''m'' is any other divisor of ''n''. For example, 6-odd-particular intervals are of the form (6''k'' + 1)/(6''k'' - 5) or (6''k'' + 5)/(6''k'' - 1).
: If ''n'' is a composite, an ''n''-odd-particular interval is between two harmonics ''n'' apart which is neither superparticular nor of ''m''-odd-particular intervals where ''m'' is any other divisor of ''n''. For example, 6-odd-particular intervals are of the form {{sfrac|6''k'' + 1|6''k'' 5}} or {{sfrac|6''k'' + 5|6''k'' 1}}.


; Ultraparticular
; Ultraparticular
: An interval/comma which is the ratio of two consecutive square-particulars.
: An interval/comma which is the ratio of two consecutive square-particulars.
: These are of the form S''k''/S(''k'' + 1).
: These are of the form {{sfrac|S''k''|S(''k'' + 1)}}.


; Semiparticular
; Semiparticular
: A superparticular or odd-particular interval/comma which is the ratio between two adjacent-to-adjacent square-particulars, which is to say:
: A superparticular or odd-particular interval/comma which is the ratio between two adjacent-to-adjacent square-particulars, which is to say:
: These are of the form S''k''/S(''k'' + 2).
: These are of the form {{sfrac|S''k''|S(''k'' + 2)}}.


; S-expression
; S-expression
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; S-factorization
; S-factorization
: An expression that takes a list of consecutive integer harmonics including the ''k''th harmonic and raises them to integer powers, similar to a [[smonzo]] but uniquely suited to analysing S-expressions.
: An expression that takes a list of consecutive integer harmonics including the ''k''th harmonic and raises them to integer powers, similar to a [[smonzo]] but uniquely suited to analysing S-expressions.
: For example: S''k'' = [''k''-1, ''k'', ''k''+1]^[-1, 2, -1] because S''k'' = (''k''-1)<sup>-1</sup>''k''<sup>2</sup>(''k''+1)<sup>-1</sup>.
: For example: {{sfrac|S''k'' {{=}} [''k'' 1, ''k'', ''k'' + 1]<sup>[−1, 2, −1]</sup>}} because {{nowrap|S''k'' {{=}} (''k'' 1)<sup>−1</sup>''k''<sup>2</sup>(''k'' + 1)<sup>−1</sup>}}.


; S-comma
; S-comma
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; Indirect S-comma
; Indirect S-comma
: Any comma that is the product or ratio of two S-commas. These appear frequently as S-expressions for commas that are more challenging/nontrivial to represent from the perspective of S-expressions, for example the [[schisma]] admits at least three such representations!
: Any comma that is the product or ratio of two S-commas. These appear frequently as S-expressions for commas that are more challenging/nontrivial to represent from the perspective of S-expressions; for example, the [[schisma]] admits at least three such representations.


== See further ==
== See further ==