Options and their associated functions

Options in xTensor` often define upvalues for associated functions. For example, the option Curvature of DefCovD defines an upvalue for the function CurvatureQ, and so on. Sometimes the option and its function share the same symbol but that is not always the case. I now find more reasonable to have a single symbol for both things: first because it is simpler to remember, second because we don`t need so many symbols; third because I don't want to have two different styles of doing the same thing.

Cases in which we have one symbol:

FrobeniusQ
Info
TensorID

Cases in which we have two symbols:

ContractThrough        ContractThroughQ
Curvature            CurvatureQ
FlatMetric            FlatMetricQ
Linear            LinearQ
FromMetric            MetricOfCovD
Torsion            TorsionQ

It always seems more reasonable to keep the symbol on the right column. Note however that Torsion is used to construct the torsion tensors and hence we need to keep it.

Then we could use only one of ContractMetric and ContractMetrics. And only one of MetricOn and UseMetricOnVBundle. Here, in both cases I would keep the first of each pair.

Created by Mathematica  (May 16, 2008)