Avoid single lesson after lunch break.

First see: How to specify when a class can have a lunch?

Question: On our school students have 6 or 7 periods in a day. In case of 6 lessons, they are on periods 1-6. In case of 7 lessons per day, they are on periods 1-5, period 6 is lunch break and then lessons on period 7-8. We do not want to have single period after lunch break. How to input this constraint?

Answer:
This is a bit tricky: You have to define three constraints to achieve this:

1) Define lunch break at periods 6-7 in menu - Specification - Classes - Details.
2) Limit max consecutive periods in class to 6. Go to menu - Specification - Card relationships - Advanced. Choose type: "Max consecutive periods of education", choose 6 in combobox below and "Apply to selected classes". Click OK.
3) Ensure at least two periods after lunch break. Go to menu - Specification - Card relationships - Advanced. Choose type: "Minimal number of periods with education per day on selected positions (empty day is ok), choose 2 in combobox below, "Apply to selected classes" and uncheck periods 1-6, so only periods 7-8 are checked. Click OK.