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m Disambiguate Rank to Rank (linear algebra) using popups
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:(''X''<sup>*</sup>, &Delta;,''X''<sub>*</sub>, &Delta;<sup>v</sup>),
where
*''X''<sup>*</sup> and ''X''<sub>*</sub> are free abelian groups of finite [[Rank (linear algebra)|rank]] together with a perfect pairing between them with values in '''Z''' which we denote by ( , ) (in other words, each is identified with the [[dual lattice]] of the other).
*&Delta; is a finite subset of ''X''<sup>*</sup> and &Delta;<sup>v</sup> is a finite subset of ''X''<sub>*</sub> and there is a bijection from &Delta; onto &Delta;<sup>v</sup>, denoted by &alpha;&rarr;&alpha;<sup>v</sup>.
*For each &alpha;, (&alpha;, &alpha;<sup>v</sup>)=2