The New Rising of the Square of Opposition (2012), p. 14
by Beziau, Jean-Yves

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Caption

Double square of oppositions

Logic

Aristotelian family

Moretti-Pellissier Sigma-4

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

Octagon (irregular)

Colinearity range

0

Coplanarity range

0

Cospatiality range

0

Representation of contradiction

By some other geometric feature

Vertex description

Conceptual info

No

Mnemonic support (AEIO, purpurea ...)

No

Form

none

Label type

none

Edge description

Style

Diagram is colored

Yes

Diagram is embellished

No