Editing registered elements
Rewriting an event
Consider the following description

To edit the second event for example, the user should highlight it, and on the Use Case menu choose Alter Event. The following dialog shows:

The user can add words or remove words and then Commit the description.
Changing a pre/postcondition
To change the precondition/postcondition for say, event two above, highlight the event and then click the Change precondition button (click change postcondition if you want to change the postcondition). The following dialog shows:

If the Change Postcondition button was clicked, the following dialog would show:

The user can then choose the new desired pre/postcondition.