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Leonardi.DB
a logical geometry project

Not Only Barbara (2015), p. 101
by Dekker, Paul

Logic

Aristotelian family
Moretti-Pellissier Sigma-4
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
Cube (regular)
Colinearity range
0
Coplanarity range
0
Cospatiality range
0
Representation of contradiction
By some other geometric feature

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

Contains definitions of relations
No
Form
solid lines
,
none
Has arrowheads
No
Overlap
No
Curved
No
Hooked
No
As wide as vertices
No
Contains text
No
Label type
none

Style

Diagram is colored
No
Diagram is embellished
No
Tags
subject negation
;
generalized Post duality

Additional notes

AäB = A'eB = $\forall x(\neg Ax \to \neg Bx)$
AxB = A'aB = $\forall x(\neg Ax \to Bx)$
AöB = A'iB = $\exists x(\neg Ax \wedge Bx)$
AyB = A'oB = $\exists x(\neg Ax \wedge \neg Bx)$

(Cf. p. 99.)

The $+$ and $-$ indicate monotonicity entailment patterns for the subject and predicate position.

This is a Moretti sigma-4 (rather than a Keynes-Johnson sigma-4), because we assume not only existential import, but also 'differential import': "The $\textit{differential import}$ of a proposition AuB is that A and B make a different proper distinction, i.e., $A \neq \emptyset \neq A'$, $B \neq \emptyset \neq B'$ and $A \neq B \neq A'$." (p. 100)

The partition induced by this diagram (subject to existential as well as differential import) consists of the following five anchor formulas:
$\bullet$ AaB
$\bullet$ AäB
$\bullet$ AeB
$\bullet$ AxB
$\bullet$ AiB $\wedge$ AoB $\wedge$ AöB $\wedge$ AyB
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