121

25

means of remedying this inconvenience.
Convention No 12 is that in such case the lines of identity may have parallels drawn on either side of them near the intersection.
Thus
X

Convention No 11 allows us to put a capital letter as the proper name of an undesignated individual.
These are called Selectives.
At first sight this device seems an admirable simplfication, and tempts us to adandon the use of lines of identity altogether.
It results however in endless complications especially in transforming the graphs.
Nevertheless, it is occasionally useful in a very high degree.

Conventions Nos 13 and 14 are perhaps the most important of all, notwithstanding my reckoning them as merely subsidiary.
I do so because they merely introduce special kinds of signs.