3

2

Use ligature in place of juncture throughout

Ladies and Gentlemen

At the end of the last lecture I gave a rule for
positively ascertaining whether a graph is alpha-
possible or not. It also furnishes a description of
the state of things in which it is possible. I said I
supposed it was not the best possible rule; but it is
reasonably speedy. Considering that the system of
existential graphs is not intended to be used as a
calculus, it satisfies all requirements

The idea of that was double correspond-
ing to two different distinctions among the six