The numbering for the second extension doesn't match (should be 3a1).
Additionally, I also feel that the first extension numbering should be 3 rather than 2 as well, since the Address Book will only detect incomplete information after the user completes his/her action, i.e. providing the required details.
Since the response from the Address Book is the same in both extension cases (i.e. throwing an error message and not clearing the input field), I feel like the ending of both extensions should match (either both "Use case ends" or "Use case continues from step 3")
The numbering for the second extension doesn't match (should be 3a1).
Additionally, I also feel that the first extension numbering should be 3 rather than 2 as well, since the Address Book will only detect incomplete information after the user completes his/her action, i.e. providing the required details.
Since the response from the Address Book is the same in both extension cases (i.e. throwing an error message and not clearing the input field), I feel like the ending of both extensions should match (either both "Use case ends" or "Use case continues from step 3")