A New Logic (1912), p. 181
by Mercier, Charles

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Caption

THE SQUARES OF OPPOSITION OF PURPOSIVE QUANTITIES.

Logic

Aristotelian family

Non-Sigma

Boolean complexity

3

Number of labels per vertex (at most)

1

Uniqueness of the vertices up to logical equivalence

No

Errors in the diagram

No

Geometry

Shape

Rectangle (irregular)

Colinearity range

0–1

Coplanarity range

0

Cospatiality range

0

Representation of contradiction

N.A.

Vertex description

Conceptual info

No

Mnemonic support (AEIO, purpurea ...)

No

Form

none

Label type

linguistic

Language

English

Lexical field

normative quantifiers

Contains partial sentences or single words

Yes

Contains abbreviations

No

Edge description

Style

Diagram is colored

No

Diagram is embellished

No

Additional notes

After collapsing the two uppermost, equivalent formulas, this basically becomes a pentagon. Its negation closure is a JSB sigma-3.