Opposition and the Syllogism (1912), p. 395
by de Laguna, Theodore

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Legend

Logic

Aristotelian family

Keynes-Johnson Sigma-4

Boolean complexity

7

Number of labels per vertex (at most)

4

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

Square (regular)

Colinearity range

0

Coplanarity range

4

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

linguistic

Language

English

Lexical field

subject negation

,

categorical

Contains partial sentences or single words

No

Contains abbreviations

Yes

Edge description

Style

Diagram is colored

No

Diagram is embellished

No