## $FCDefaultLightconeVectorNB

`$FCDefaultLightconeVectorNB` is  a global variable which is set to FCGV["nb"]. It denotes the default name for the vector $\bar{n}$ in the lightcone decomposition for Lorentz tensors.

### See also

[Overview](Extra/FeynCalc.md), [MemSet](MemSet.md), [FCMemoryAvailable](FCMemoryAvailable.md).

### Examples

```mathematica
$FCDefaultLightconeVectorNB
```

$$\text{FCGV}(\text{nb})$$