Ideally, I would like to do this :

```
@w: 4px;

@media (max-width:900px) {
    @r: 3px; 
}
@media (min-width:900px) {
    @r: 5px; 
}

.myclass {
    border-radius: @w + @r;
}

```

This doesn't compile because `@r` isn't defined in the scope where I define `.myclass`. The obvious solutions are either to define `.myclass` inside the `@media` blocs or to copy the `@media` queries inside the definition of `.myclass`.

But as soon as you use `@r` in many classes, both solutions are messy and involve many duplications.

Is there a clean dry solution ?