Hi Troops,

Here is s short Cadabra code

```
{a,b,c,d,e,f#}::Indices(position=independent).
R_{a b c d}::RiemannTensor.
# this should give zero
foo := (1+s) R_{a b c d} p^{a} p^{b} p^{c} p^{d}.
canonicalise (foo);
# this gives the expected result
bah := s R_{a b c d} p^{a} p^{b} p^{c} p^{d}.
canonicalise (bah);
```

There are two ouputs `foo`

and `bah`

. Both should be zero (beacuse of the symmetries of the Riemann tensor). But only `bah`

is correctly given as zero. This seems like a bug to me.

Cheers, Leo