_\______
a / / \ /\ /\ / \ \ e
/ / \ / \ / \ / \ \
/ \ \/ \/ \/ / \
/ \ /\ /\ /\ / \
/ \ / \ / \ / \ / \
| \/ \/ __ \/ \/ |
| /\ /\/ \/\ /\ |
| / \ / /\ /\ \ / \ |
| | \/ | \/ | \/ | |
| | /\ | /\ | /\ | |
| \ / \ \/ \/ / \ / |
\ \/ \/\__/\/ \/ /
\ /\ /\ /\ /\ /
\ / \ / \ / \ / \ /
\ / \/ \/ \/ \ /
\ \ /\ /\ /\ / /
\ \ / \ / \ / \ / /
\ \/ \/ \/ \/ /
\ /\____/\____/\____/\ /
\ / \ /
\| |/
\____________________/
pg176
This Diagram gives us 31 closed compartments.

For _six_ letters, Mr. Venn suggests that we might use _two_ Diagrams,
like the above, one for the f-part, and the other for the not-f-part, of
all the other combinations. "This", he says, "would give the desired 64
subdivisions." This, however, would only give 62 closed Compartments,
and _one_ infinite area, which the two Classes, a'b'c'd'e'f and
a'b'c'd'e'f', would have to share between them.

Beyond _six_ letters Mr. Venn does not go.

Sec. 7.

_My Method of Diagrams._

My Method of Diagrams _resembles_ Mr. Venn's, in having separate
Compartments assigned to the various Classes, and in marking these
Compartments as _occupied_ or as _empty_; but it _differs_ from his
Method, in assigning a _closed_ area to the _Universe of Discourse_, so
that the Class which, under Mr. Venn's liberal sway, has been ranging at
will through Infinite Space, is suddenly dismayed to find itself
"cabin'd, cribb'd, confined", in a limited Cell like any other Class!
Also I use _rectilinear_, instead of _curvilinear_, Figures; and I mark
an _occupied_ Cell with a 'I' (meaning that there is at least _one_
Thing in it), and an _empty_ Cell with a 'O' (meaning that there is _no_
Thing in it).

For _two_ letters, I use this Diagram, in which the North Half is
assigned to 'x', the