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

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Caption

Two over the four kinds of opposition relations of the square are now visible.

Logic

Aristotelian family

Classical Sigma-7

Boolean complexity

4–5

Number of labels per vertex (at most)

0

Uniqueness of the vertices up to logical equivalence

Yes

Errors in the diagram

No

Geometry

Shape

Tetrahedron (regular)

Colinearity range

1

Coplanarity range

1

Cospatiality range

0

Representation of contradiction

By diametric opposition (but no central symmetry)

Vertex description

Conceptual info

No

Mnemonic support (AEIO, purpurea ...)

No

Label type

none

Edge description

Style

Diagram is colored

No

Diagram is embellished

No

Tags

existential import

Additional notes

3 of the 14 vertices are not explicitly drawn.