not add anything to our information to put a "I" on the fence.
The Diagram _already_ tells us that "Some m are x".]

a b c
.---------------. .---------------. .---------------.
| | | |(O) | | |(O) | |
| .---|---. | | .---|---. | | .---|---. |
| | | | | | | | | | | |(I)| | |
|---|---|---|---| |---|---|---|---| |---|---|---|---|
| |(O)|(O)| | | |(O)|(O)| | | |(O)|(O)| |
| .---|---. | | .---|---. | | .---|---. |
| | | |(O) | | |(O) | |
.---------------. .---------------. .---------------.

[Work Examples Sec. =1=, 9-12 (p. 97); Sec. =2=, 1-20 (p. 98).]

pg053

CHAPTER IV.

_INTERPRETATION, IN TERMS OF x AND y, OF TRILITERAL DIAGRAM, WHEN MARKED
WITH COUNTERS OR DIGITS._

The problem before us is, given a marked Triliteral Diagram, to
ascertain _what_ Propositions of Relation, in terms of x and y, are
represented on it.

The best plan, for a _beginner_, is to draw a _Biliteral_ Diagram
alongside of it, and to transfer, from the one to the other, all the
information he can. He can then read off, from the Biliteral Diagram,
the required Propositions. After a little practice, he will be able to
dispense with the Biliteral Diagram, and to read off the result from the
Triliteral Diagram itself.

To _transfer_ the information, observe the following Rules:--

(1) Examine the N.W. Quarter of the Triliteral Diagram.

(2) If it contains a "I", in _either_ Cell, it is certainly
_occupied_, and you may mark the N.W. Quarter of the
Biliteral Diagram with a "I".

(3) If it contains _two_ "O"s, one in _each_ Cell, it is
certainly _empty_, and you may mark the N.W. Quarter of the
Biliteral Diagram with a "O".
pg054
(4) Deal in the same way with the N.E., the S.W., and the
S.E. Quarter.

[Let us take, as examples, the results of the four Examples
worked in the previous Chapters.

(1)
.---------------.
|(O) | (O)|
| .---|---. |
| | |(O)| |
|---|---|---|---|
| | |(O)| |
| .---|---. |