laboratory where the apparatus is deposited; it must show to the
instructor what experiments have been performed by each student; it must
prevent the assignment of the same experiment to two students; it must
enable the instructor to assign the same experiment to two or more
students; it must form a complete record of what has been done, what
work is incomplete, and what experiments have not yet been assigned; it
must also be so arranged that new experiments or sets of experiments may
be exhibited.

+------+---+---+---+---+---+---+---+---+
| | A | B | C | D | E | F | G | H |
+------+---+---+---+---+---+---+---+---+
| 1 | * o o * o o o o |
| 2 | * o * * o o o o |
| 3 | + * * * o o o o |
| 4 | + o * * o o o o |
| 5 | o + * * * * o o |
| 6 | o + * * o * o o |
| 7 | o o + * o o o o |
| 8 | o o o + * o o o |
| 9 | o o o * + o o o |
| 10 | o o o o o + o o |
| 11 | o o o * o o + * |
| 12 | o o * * o + + + |
| 13 | o o * o o o o o |
| 14 | o o * o o o o o |
| 15 | o o + o o o o o |
| 16 | o o + + * o o * |
+--------------------------------------+