MS NAV v4.2.active logging functionality ?

I have this scenario

The client is using MS NAV v4.2. Users on the system have been set up in three groups, each of which has a number of users assigned to it. Despite this subdivision, all three groups have the same permissions i.e. access is the same across the board. The client has informed us that logs are not available for the period under review. Nevertheless, we would like to make sure that this is really the case.

Is there any way in which we could assess whether there is any active logging functionality on the system? If so, is it possible to know for which functions these logs are switched on?

Thanks

The only “logging” functionality in NAV is Change Log. Is that what you are talking about?

Can you provide more details. I have no knowledge of Change Log of Navision. (i need more explanation by Experts on NAV on this field) . Thanks