createExam(ident uid, ident id, ident eid, string title, string date, string time, string location) {
  assume exists /account[uid]/admin;
 
  assume not exists /exam[id];
  assume exists /exercise[eid];
 
  insert /
    <exam id=[id] title=[title] date=[date] time=[time] location=[location] free=[false] published=[false] exercise=[eid] />
}