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Leonardi.DB
a logical geometry project

# Peri hermeneias (975–1025), fol. 39v by Apuleius, Lucius

### Logic

Aristotelian family
Classical Sigma-2
Boolean complexity
3
Number of labels per vertex (at most)
1
Uniqueness of the vertices up to logical equivalence
Yes
Errors in the diagram
No

### Geometry

Shape
Circle (regular)
Colinearity range
0
Coplanarity range
0
Cospatiality range
0
Representation of contradiction
By central symmetry

### Vertex description

Conceptual info
Yes
Mnemonic support (AEIO, purpurea ...)
No
Form
square
Label type
symbolic
Symbolic field
logic
Contains partial formulas or symbols
Yes
Logical system
syllogistics

### Edge description

Contains definitions of relations
No
Form
bands
Has arrowheads
No
Overlap
No
Curved
Yes
Hooked
No
As wide as vertices
Yes
Contains text
Yes
Label type
linguistic
Language
Latin
Contains partial sentences or single words
Yes
Contain abbreviations
Yes

### Style

Diagram is colored
No
Diagram is embellished
No
Tags
diagram chasing

### Additional notes

The letters A, B, C, D are used as we would later use A, E, I, O. Concretely: A stands for the universal affirmative statement, B stands for the universal negative statement, C stands for the particular affirmative statement, and D stands for the particular negative statement.

This diagram fully describes the relations between truth values of the four vertices. For example, starting from the vertical line at 12 o'clock and moving clockwise to the horizontal line at 3 o'clock, we read:

* C: si falsum est, astruitur B=> cf. contradiction between B and C
* D: si falsum est, destruitur B=> cf. subalternation from B to D
* A: si verum est, destruitur B=> cf. contrariety between A and B
* C: si verum est, destruitur B=> cf. contradiction between B and C