From the Square to Octahedra (2017), p. 271
by García-Cruz, José David
Copyright according to our policy
Caption
- First-order inversion octagon
- 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
- Octagon (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 ...)
- No
- Form
- none
- Label type
- symbolic
- Symbolic field
- logic
- Contains partial formulas or symbols
- No
- Logical system
- syllogistics ,
- predicate logic
- 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
Vertex description
Edge description
- Diagram is colored
- Yes
- Diagram is embellished
- No
- Tags
- subject negation ;
- generalized Post duality
Style
Additional notes
- 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).