changeAttributes(ident uid, ident id, ident taskId, double maxPoints) {
  assume exists //accounts/account[uid]/examiner[id];
 
  assume exists //exams/exam[id]/tasks/task[taskId]; # implies the existence of the exam
 
  assume maxPoints >= 0;
  assume //exams/exam[id]/results/participant[x]/result[taskId]/points <= maxPoints;
 
  update //exams/exam[id]/tasks/task[taskId]/maxPoints maxPoints;
}