## SUNN

`SUNN` denotes the number of colors. `Trick[SUNDelta[a, a]]` yields $n_c^2 -1$.

### See also

[Overview](Extra/FeynCalc.md), [SUNSimplify](SUNSimplify.md), [Trick](Trick.md), [SUNIndex](SUNIndex.md), [CA](CA.md), [CF](CF.md).

### Examples

```mathematica
SUNSimplify[SUNDelta[SUNIndex[a], SUNIndex[a]], SUNNToCACF -> False]
```

$$N^2-1$$