Hi,

I was just trying a simple computation and ran into a possible bug in evaluate. The following code works as expected:

```
{a,b,c,d,e,f#}::Indices(position=independent,values={x,y,z}).
{x,y,z}::Coordinate.
dot_g := -2 K_{a b}; # okay
# dot_g := -2 N K_{a b}; # crash
Kdn=[]
for a in ["x","y","z"]:
for b in ["x","y","z"]:
Kdn.append("K_{"+a+" "+b+"} = K"+a+b)
Kdn_rl = Ex(','.join(Kdn));
evaluate (dot_g,Kdn_rl,rhsonly=True);
```

But if you un-comment the 4th line an error pops up:

```
TypeError: unsupported operand type(s) for *: 'Integer' and 'function'
```

Cheers,

Leo