67

64

Permission No 7. A vacant cut may be
treated as a pseudograph.

These seven permissions being, however,
somewhat confusing, I replace them by a
compact little code which I call the three
primary rules. It runs as follows:

Erasure and Insertion. Within even
cuts (or none) any graph can be erased;
and within odd cuts any graph can be
inserted.

Rule of Iteration and Deiteration.
Any graph of which a replica is already scribed
may be iterated on
the same area as the primitive replica
or within any additional cuts already
existing; and of two replicas of the same