Hi, I was wondering whether (or how) I can tell Cadabra to treat an object like a parameter, not like a (rank-0) tensor. I have the following code:

```
{i,j,k}::Indices(vector);
N::Integer;
{i,j,k}::Integer(1..N);
_ := S^{i}\_{j}^{k} S\_{i}^{j}\_{k} + 15*N*S^{i j k} S\_{i j k};
canonicalise(_);
sort_sum(_);
```

The output is $S^{ijk} S_{ijk} + 15N S^{ijk} S_{ijk}$.

However, I would like Cadabra to collect terms pretending that $N$ is just a number, i.e. I would like the result to be $(1+15N) S^{ijk} S_{ijk}$.

Is it possible?