MS 455-456 (1903) - Lowell Lecture II

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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

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graph, one of which is enclosed by every cut that encloses the other, the former may be erased, this process being termed deiteration.

Rule of Insignificants and the Pseudograph A double cut enclosure can anywhere be inserted and anywhere erased can be circumposed about any graph or be removed from any graph; and the area cont any enclosure containing a vacant cut or other form of pseudograph can be suppressed or inserted.

Now go to p 18