canIStart

function canIStart(){
  var missingExams = this.get('exams').where({'done': false});
  var examsINF = missingExams.where({'class': 'INF'});
  var examsMAT = missingExams.where({'class': 'MAT'});
  var examING = missingExams.where({'name': 'Ingegneria del Software'}).first();
  if (examsINF.count()>1 || examsMAT.count()>2)
    return false;
  if (examING && examING.progress()<0.5)
   return false;
  return true;
}