PairQ

• PairQ[a, b] gives True if indices a, b form an Einstein pair of contracted indices.

• Currently this is only possible for a pair a, -a of abstract indices or a pair {a, basis}, {-a, -basis} of basis indices of the same basis basis.
• See: Section 2.1.
• See also: EIndexQ, ContractMetric.
• New in version 0.
• Last update: 16-V-2008 for version 0.9.5 of xTensor`.

Created by Mathematica  (May 16, 2008)