From the Square to Octahedra (2017), p. 269
by García-Cruz, José David
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Caption
- Traditional 2PH
- Aristotelian family
- Keynes-Johnson Sigma-4
- Boolean complexity
- 7
- Number of labels per vertex (at most)
- 1
- Uniqueness of the vertices up to logical equivalence
- Yes
- Errors in the diagram
- No
- Shape
- Hexagonal Bipyramid (irregular)
- Colinearity range
- 0
- Coplanarity range
- 0
- Cospatiality range
- 0
- Representation of contradiction
- By central symmetry
Logic
Geometry
- Conceptual info
- No
- Mnemonic support (AEIO, purpurea ...)
- Yes
- Form
- none
- Label type
- symbolic
- Symbolic field
- logic
- Contains partial formulas or symbols
- Yes
- Logical system
- syllogistics
- Contains definitions of relations
- No
- Form
- solid lines
- Has arrowheads
- Yes
- Overlap
- No
- Curved
- No
- Hooked
- No
- As wide as vertices
- No
- Contains text
- No
- Label type
- none
Vertex description
Edge description
- Diagram is colored
- Yes
- Diagram is embellished
- No
- Tags
- subject negation ;
- generalized Post duality
Style
Additional notes
- Aab = all a are b
Eab = no a are b
Iab = some a are b (mistakenly displayed as Lab in the diagram)
Oab = some a are not b
Rab = all non-a are non-b = all b are a
Sab = no non-a are non-b = all non-a are b
Tab = some non-a are non-b
Uab = some non-a are not non-b = some non-a are b
(Cf. p. 254 and p. 257.)
Under the assumption of existential import, this diagram is a Keynes-Johnson sigma-4 (Boolean complexity 7).
If we would make the additional assumption of 'differential import' (cf. Dekker 2015), this diagram would be a Moretti sigma-4 (Boolean complexity 5).