Hi,

In Cadabra 2.2.0 I am having some trouble cancelling numerical factors involving powers of 1/2 and minus 1/2.

For instance, if I evaluate

```
$2 1/2$;
```

Cadabra outputs correctly 1.

However if I evaluate

```
$2**(1/2) 2**(-1/2)$;
```

Cadabra outputs in TeX \sqrt{2} 2^{-1/2} and does not combine these.

If I try to make it do so using collect*factors(*), I get a "The kernel crashed unexpectedly" message. (And actually I notice this happens in Cadabra 1 too...)

Conversely, it collects_factors correctly for

```
$X**(1/2) X**(-1/2)$;
collect_factors(_);
```

Is this meant to happen? Am I missing some very basic instruction on how to treat numbers?

Thanks!