Hello,

In FreeFEM, is it possible to deal with a time dependent non linear problem like this one :

```
\nabla^2 A = - \sigma(dA/dt) * dA/dt
```

with sigma, a non linear function.

I saw that I must use a `uold`

variable for the time-dependent part, and `uu`

for the non linear part, but how can I mix both of them. Should I create a `uuold`

maybe ?

Thank you in advance,

Best regards,

Jeremie