A set of activities begins teacher's day

[xtzetzias]

Hi,
could someone please explain to me how does this constraint work? I cannot find it in the "Documentation" section and my experiments are not enlightening :-(

[YOUSSEF HOUIET]

The purpose of this constraint is to ensure that these activities are placed by the program as the first activity in the teacher's working day, and not inserted in the middle of the teacher's other lessons.

[xtzetzias]

Thank you Youssef!
I was expecting something different: that other activities cannot be placed before the chosen ones. That's why it didn't make sence.
So, if i understand correct, they cannot be more than 5 subactivities in this set (given that the week has 5 days)?