User:Inthar/MV3: Difference between revisions

Inthar (talk | contribs)
Inthar (talk | contribs)
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Below, assume that the scale word S is not multiperiod.
Below, assume that the scale word S is not multiperiod.


=== Lemma 1: S is pairwise-well-formed (PWF), i.e. sizes of chunks of any fixed letter form a MOS (except in the case "xyzyx") ===
=== Lemma 1: S is PWF (except in the case "xyzyx") ===
TODO: account for case xyzyx.
TODO: account for case xyzyx.


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''To be continued...''
''To be continued...''


=== PWF implies the alternating-gens (AG) property (except in the case xyxzxyx) ===
=== PWF implies AG (except in the case xyxzxyx) ===
We now prove that except in the case xyxzxyx, if the scale is pairwise well-formed, the scale is generated by two chains of generators, either both of size ''m'' or one with size ''m'' and one of size ''m-1'' (AG) Equivalently, the scale can be built by stacking alternating generators, resulting in a circle of the form  either g1 g2 ... g1 g2 g1 g3 or g1 g2 ... g1 g2 g3.
We now prove that except in the case xyxzxyx, if the scale is pairwise well-formed, the scale is generated by two chains of generators, either both of size ''m'' or one with size ''m'' and one of size ''m-1'' (AG) Equivalently, the scale can be built by stacking alternating generators, resulting in a circle of the form  either g1 g2 ... g1 g2 g1 g3 or g1 g2 ... g1 g2 g3.