Hello,

I have a question about the evaluation of a tensor contracted with Gamma matrices. First I defined the indices and Gamma matrices by

```
{a,b,c,d}::Indices(position=fixed);
{a,b,c,d}::Integer(0..2);
\Gamma{#}::GammaMatrix(metric=\eta);
\eta_{a b}::KroneckerDelta;
C_{a b c}::AntiSymmetric;
```

Then what I want to evaluate is

```
ex:= C_{a b c} \Gamma^{a b c};
```

by using an explicit value:

```
rl:= [ C_{0 1 2} = \alpha ];
```

However, performing evaluate(ex, rl); , I got 0, which is different from what I expected to get, 6 \alpha \Gamma^{0 1 2}. Could anyone help me? Many thanks.