Hi
I have a little problem with above constrain. For example teacher's available time is from Monday to Thursday (8h per day). It's 32h available time and teacher have 18h of activities. But on Monday he have to start at first hour (any activities) and on Wednesday he have to end on eight hour (also any activities). He can't have any gaps, min. 3 hours a day, max. 8 hours a day. That 3 constrains are very easy to do, but how to make a teacher to start or end any lesson on specific hour and day??
To constrain the teacher to have any activity in a specified slot, use constraint activities occupy max time slots from selection (in your case, two constraints, one for Monday first hour and the other for Wednesday the eighth hour). Read the help for this constraint for how to do that (press the Help button in the dialog), and come back here if you need more help.
Edit: a single constraint will suffice.
Thank you very much for help!! It works perfectly. I added one constrain "A set of activities occupies max time slots from selection", followed with the help explanation and it WORKS!!
I improved my answer above, based on your observation that a single constraint will suffice.