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Leonardi.DB
a logical geometry project

Was Lewis Carroll an Amazing Oppositional Geometer? (2014), p. 400
by Moretti, Alessio

Caption

Carroll’s 4-partition of truth (with respect to the predications possible in his logic).

Logic

Aristotelian family
Contrariety 4-clique
Boolean complexity
4
Number of labels per vertex (at most)
1
Uniqueness of the vertices up to logical equivalence
Yes
Errors in the diagram
No

Geometry

Shape
Tetrahedron (regular)
Colinearity range
0
Coplanarity range
0
Cospatiality range
0
Representation of contradiction
N.A.

Vertex description

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

Edge description

Style

Diagram is colored
Yes
Diagram is embellished
No
Tags
existential import

Additional notes

The negation closure of this diagram is a Moretti-Pellissier sigma-4.

Consider the following partition:
1) A! (all x are y, and there is at least one x)
2) I $\wedge$ O (some x are y and some x are not y)
3) E! (no x are y, and there is at least one x)
4) there are no x

With the bitstrings based on this partition, the formulas of this diagram (in Greek notation) can be represented as follows:

1000 = $ \alpha\beta\delta $
0100 = $ \alpha\beta\gamma $
0010 = $ \alpha\gamma\delta $
0001 = $ \beta\gamma\delta $
1100 = $ \alpha\beta $
1010 = $ \alpha\delta$
1001 = $ \beta\delta $
0110 = $ \alpha\gamma $
0101 = $ \beta\gamma $
0011 = $ \gamma\delta $
1110 = $ \alpha $
1101 = $ \beta $
1011 = $ \delta $
0111 = $ \gamma $

Note: $\alpha\beta$ means $\alpha\wedge\beta$ (cf. p. 391).
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