BIndexQ

• BIndexQ[expr] gives True if expr is a valid basis-index: {i, basis} or {-i, -basis} where i is a contravariant abstract-index.
• BIndexQ[expr, basis] gives True if expr is a valid basis-index belonging to basis.
• BIndexQ[expr, vbundle] gives True if expr is a valid basis-index belonging to vbundle or to a subvbundle of vbundle.

• The correspondence between the abstract index and the basis is checked, using the function VBundleOfBasis in xCoba`.
• See: Section 2.3.
• See also: CIndexQ, BCIndexQ, ABIndexQ, GIndexQ.
• New in version 0.
• Last update: 24-IX-2007 for version 0.9.3 of xTensor`.

Created by Mathematica  (May 16, 2008)