Theophrastische Modallogik (1969), p. 74
by Lorenzen, Paul

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Logic

Aristotelian family

Non-Sigma

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

Rectangle (irregular)

Colinearity range

0–1

Coplanarity range

3

Cospatiality range

0

Representation of contradiction

N.A.

Vertex description

Conceptual info

No

Mnemonic support (AEIO, purpurea ...)

No

Form

none

Label type

symbolic

Symbolic field

logic

Contains partial formulas or symbols

Yes

Logical system

modal logic

Edge description

Style

Diagram is colored

No

Diagram is embellished

No

Additional notes

$\triangle p$ = it is necessary that $p$ (cf. p. 72).
$\triangledown p$ = it is possible that $p$ (cf. p. 73).
$\mathsf{X} p$ = it is true that $p$ (cf. p. 74).
$\hat{\times} p$ = $\mathsf{X}p \wedge \neg\triangle p$ (cf. p. 74).
$\diamond p$ = $\triangledown p \wedge \neg\triangle p$ (cf. p. 74).

The negation closure of this diagram is a sigma-6 diagram.