/* 
   EyeDB Object Database Management System
   Copyright (C) 1994-1999,2004-2006 SYSRA
   
   EyeDB is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.
   
   EyeDB is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.
   
   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA 
*/

/*
   Author: Eric Viara <viara@sysra.com>
*/


class Person {
  attribute string firstname;
  attribute string lastname;
};

class Student extends Person {
  attribute short begin_year;
  relationship set<Course *> courses inverse students;
};

class Course {
  attribute string title;
  attribute string description;
  relationship set<Student *> students inverse courses;
  relationship Teacher *teacher inverse courses;
};

class Teacher extends Person {
  relationship set<Course *> courses inverse teacher;
};