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Leonardi.DB
a logical geometry project

Probabilistic squares and hexagons of opposition under coherence (2017), p. 290
by Pfeifer, Niki; Sanfilippo, Giuseppe

Caption

Probabilistic hexagon of opposition defined on the six sentence types $(s_1, s_2, s_3, s_4, s_5, s_6)$, where $(s_1, s_2, s_3, s_4)$ is a square of opposition, $s_5 = s_1 \vee s_2$, and $s_6 = s_3 \wedge s_4$ (see Definition 12). The arrows indicate subalternation, dashed lines indicate contraries, and dotted lines indicate sub-contraries. Contradictories are indicated by combined dotted and dashed lines.

Logic

Aristotelian family
Jacoby-Sesmat-Blanché Sigma-3
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
Hexagon (regular)
Colinearity range
0
Coplanarity range
0
Cospatiality range
0
Representation of contradiction
By central symmetry

Vertex description

Conceptual info
No
Mnemonic support (AEIO, purpurea ...)
No
Form
none
Label type
generic placeholders

Edge description

Style

Diagram is colored
Yes
Diagram is embellished
No
Tags
Boolean closed

Additional notes

On p. 290 it is stated that $s_5 = s_1 \vee s_2$ and $s_6 = \overline{s}_1 \wedge \overline{s}_2 = s_4 \wedge s_3$. Hence, this diagram is a strong JSB hexagon (with Boolean complexity 3).
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