One of period 5 or 6 must be free .

[TAHIR]

For the selected teacher(s), at least one of Period 5 or Period 6 must be free.how we add constraint ?

[Liviu Lalescu]

Very easy:

1) Teacher(s) pair of mutually exclusive time slots. Add n_days_per_week constraints;

or

2) Teacher(s) max hours daily in hourly interval.

I prefer (1).

[TAHIR]

Please explain both of these methods.

[Liviu Lalescu]

Please try finding these constraints in the menu and using them! If you still cannot succeed, I'll try to answer tomorrow.

[Liviu Lalescu]

1) Add n_days_per_week constraints. Teacher(s) pair of mutually exclusive time slots. Select Monday, 5, as first slot, and Monday, 6, as second slot. Same Tuesday,..., Friday.

2) Teacher(s) max 1 hours per day in hourly interval [5, 7).

Did you succeed now?