Talk:The Seven Limit Symmetrical Lattices/WikispacesArchive

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Question about [a b c] notation

I'm confused by this sentence:

"The 4:5:6:7 major tetrad consists of the notes |* 0 0 0>, |* 1 0 0>, |* 0 1 0>, and |* 0 0 1>; the centroid of this is |* 1/2 1/2 1/2>; similarly the centroid of 1/4:1/5:1/6:1/7 is |* -1/2 -1/2 -1/2>. If we shift the origin to |* 1/2 1/2 1/2>, major tetrads correspond to [a b c], a+b+c even, and minor tetrads to [a-1 b-1 c-1], a+b+c even, which is the same as saying [a b c], a+b+c odd"

This [a b c] notation wasn't defined anywhere on the page. What does it mean, and how does it define a tetrad, rather than an interval?

- mbattaglia1 September 15, 2011, 12:29:35 AM UTC-0700

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I'm going to rewrite this old posting.

- genewardsmith September 15, 2011, 09:16:55 AM UTC-0700

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