Was Lewis Carroll an Amazing Oppositional Geometer? (2014), p. 395
by Moretti, Alessio

Copyright according to our policy

Caption

The 'oppositional hexagon' (or 'logical hexagon') contains three oppositional squares. - the logical hexagon

Logic

Aristotelian family

Jacoby-Sesmat-Blanché Sigma-3

Boolean complexity

3

Number of labels per vertex (at most)

2

Equivalence between (some) labels of the same vertex

Yes

Analogy between (some) labels of the same vertex

No

Uniqueness of the vertices up to logical equivalence

Yes

Errors in the diagram

No

Geometry

Shape

Hexagon (regular)

Colinearity range

0

Coplanarity range

0

Cospatiality range

0

Representation of contradiction

By central symmetry

Vertex description

Conceptual info

No

Mnemonic support (AEIO, purpurea ...)

Yes

Form

dots

Label type

symbolic

Symbolic field

logic

Contains partial formulas or symbols

Yes

Logical system

syllogistics

Edge description

Style

Diagram is colored

Yes

Diagram is embellished

No

Tags

Boolean closed

;

existential import