Query for advanced find of accounts whose contacts has not had appointment

Hi! 
I want to set up a personal view with the following criteria

Active Accounts where account address 1 equals a specific city, or no data in adress 1 city. Only view those accounts who has contacts, and only view those accounts whose contact has not had an appointment the last 6 months or ever. 

The active and city-part is fine. But Im struggling with the query for accounts whose contacts has not had an appointment. Meaning that if only 1 contact under an account has had an appointment, the account should not be visible in this view. 

Would also like to add that the appointments in regarding contacts, not regarding accounts. 

Thank you,

Best,

Kristin