On Maintenance of the Opportunity List for Class-Teacher Timetable Problems One of the principal components of procedures for the solution of class-teacher timetable problems is that for maintenance of the opportunity list. Opportunity list maintenance methods are based on necessary conditions for the existence of a solution. A general framework for necessary conditions, together with four specific sets of necessary conditions, is given. CACM April, 1975 Smith, G. combinatorial, necessary conditions, opportunity list, schedule,school timetable, timetable 3.51 5.39 CA750405 JB January 9, 1978 4:03 PM 1367 4 2772 2619 4 2772 2772 4 2772 2772 4 2772 2787 4 2772 2787 4 2772 1116 5 2772 1429 5 2772 2772 5 2772 2772 5 2772 2772 5 2772