You're using an ancient browser to surf the modern web. Please update to the latest version (and don't use Internet Explorer!).

Leonardi.DB
a logical geometry project

Was Lewis Carroll an Amazing Oppositional Geometer? (2014), p. 392
by Moretti, Alessio

Caption

Carroll's first logical chart negates some squares which seemed plausible.

Logic

Aristotelian family
Degenerate Sigma-2 with Unconnectedness 4
Boolean complexity
4
Number of labels per vertex (at most)
1
Uniqueness of the vertices up to logical equivalence
Yes
Errors in the diagram
No

Geometry

Shape
Trapezoid (irregular)
Colinearity range
0
Coplanarity range
0
Cospatiality range
0
Representation of contradiction
By diametric opposition (but no central symmetry)

Vertex description

Conceptual info
No
Mnemonic support (AEIO, purpurea ...)
No
Form
dots
Label type
linguistic
Language
English
Lexical field
syllogistics
Contains partial sentences or single words
No
Contains abbreviations
Yes

Edge description

Style

Diagram is colored
Yes
Diagram is embellished
No
Tags
subdiagram
;
existential import

Additional notes

Consider the following partition:
1) A! (all x are y, and there is at least one x)
2) I $\wedge$ O (some x are y and some x are not y)
3) E! (no x are y, and there is at least one x)
4) there are no x

With the bitstrings based on this partition, the formulas of this diagram (in vernacular notation) can be represented as follows:

1000 = all x are y
0100 = some x are y and some x are y'
0010 = all x are y'
0001 = there are no x
1100 = some x are y
1010 = all x are y or all [x] are y'
1001 = no x are y'
0110 = some x are y'
0101 = not all x are y nor are all y' [not all x are y and not all x are y']
0011 = no x are y
1110 = some x exist
1101 = not all x are y'
1011 = no x are y or none [i.e. no x] are y'
0111 = not all x are y
↑ Back to top ↑