Create sub-axes when 'alternative' is active
When alternative is selected on an axis create sufficient sub-axes:
- If "exactement n" or "au moins n", it should create n+1 axis.
- If "entre n et p", then it should create p axis.
When alternative is selected on an axis create sufficient sub-axes:
- If "exactement n" or "au moins n", it should create n+1 axis.
- If "entre n et p", then it should create p axis.