Hi,

I want to use dotted and undotted indices in order to get as close as possible to superspace notations, but I have problems with the dotted ones. For example

```
\dot{#}::Symbol;
{\dot{\alpha}, \dot{\beta}, \dot{\gamma}, \dot{\delta}}::Indices(spinor, position=fixed);{\dot{\alpha}, \dot{\beta}, \dot{\gamma}, \dot{\delta}}::Integer(1..2);
\nabla{#}::Derivative;
ex:=\nabla^{\dot{\gamma}}(\theta^{\dot{\alpha}}) \theta_{\dot{\alpha}};
substitute(_, $\nabla^{\dot{\alpha}}(\theta^{\dot{\beta}}) -> epsilon^{\dot{beta} \dot{\alpha}}$);
```

does nothing, while, if I remove all dots everything works fine. Moreover, if I give a name to my substitution like

`dt:=\nabla_{\dot{\alpha}}(\theta^{\dot{\beta}}) -> \delta_{\dot{\alpha}}^{\dot{\beta}}`

and I call again the substitution command

`substitute(_, dt);`

messes up indices completly. Again, if I use the same code with undotted indices, it works just fine.

I am not sure this is a bug or I do not do things in the right way. I also had problems with \bar (wanted to use \bar{\theta}) and Cadabra was setting this to 0 after certain commands. I will get back to that if it is not related to the dotted promble above.

Thanks, Andrei