Quadratum auctum (1984), p. 324
by Englebretsen, George

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Logic

Aristotelian family

Non-Sigma

Boolean complexity

5

Number of labels per vertex (at most)

1

Uniqueness of the vertices up to logical equivalence

Yes

Errors in the diagram

No

Geometry

Shape

Hexagon (irregular)

Colinearity range

0

Coplanarity range

0

Cospatiality range

0

Representation of contradiction

N.A.

Vertex description

Conceptual info

Yes

Mnemonic support (AEIO, purpurea ...)

Yes

Form

none

Label type

symbolic

Symbolic field

logic

Contains partial formulas or symbols

Yes

Logical system

syllogistics

Edge description

Style

Diagram is colored

No

Diagram is embellished

No

Additional notes

The negation closure of this diagram (which is obtained by adding the negations of a and e) is a Lenzen sigma-4.