Delete Task

deleteTask(ident uid, ident id, ident taskId) {
  assume exists /account[uid]/examiner[id];
 
  assume exists /exam[id]/task[taskId]; # implies the exam exists, which is implicitly true anyway
 
  assume size(/exam[id]/participant/result[taskId]) = 0;
 
  remove /exam[id]/task[taskId];
}