Each teacher shall have one or two free afternoon

The bellow constraint will define that each teacher has 2 free afternnons:

Basically it says, teacher can have max 3 days with lessons on the positions marked on the time map. Make sure you input correctly all the marked entries.

Notes:
- In our example afternoon was defined as periods 5th and above. You can change this by clickin in the time map.
- same condition can be defined for mornings, again just change the map
- you can select only some teachers that shall be considered