Exactly one of four relations for graph parameters
Lax825442.RelationClassification · concepts/Lax825442/RelationClassification.lean · lax-825442
No public endorsements yet.
Loading review…
Sign in with ORCIDNatural Language Statement
Theorem
For every pair of graph parameters, exactly one of four relations holds: the first strictly bounds the second, the second strictly bounds the first, they are functionally equivalent, or they are incomparable.
The statement asserts that at least one case holds and explicitly excludes all six pairs of simultaneous cases. Its proof uses classical excluded middle for functional boundedness in each direction; it does not provide an algorithm for deciding which case holds.
Concept map
Evidence
Each proof establishes this claim relative to its assumptions.
Lean source view on GitHub
| 1 | import Lax825442.StrictlyBounds |
| 2 | import Lax825442.Equivalent |
| 3 | import Lax825442.Incomparable |
| 4 | |
| 5 | /-! |
| 6 | --- |
| 7 | title: Exactly one of four relations for graph parameters |
| 8 | type: theorem |
| 9 | --- |
| 10 | For every pair of graph parameters, exactly one of four relations holds: |
| 11 | the first strictly bounds the second, the second strictly bounds the first, |
| 12 | they are functionally equivalent, or they are incomparable. |
| 13 | |
| 14 | The statement asserts that at least one case holds and explicitly excludes |
| 15 | all six pairs of simultaneous cases. Its proof uses classical excluded |
| 16 | middle for functional boundedness in each direction; it does not provide an |
| 17 | algorithm for deciding which case holds. |
| 18 | -/ |
| 19 | |
| 20 | namespace Lax825442.RelationClassification |
| 21 | open Lax153141.GraphParameters |
| 22 | open Lax825442.StrictlyBounds Lax825442.Equivalent Lax825442.Incomparable |
| 23 | |
| 24 | /-- Exactly one of the four cases holds: exhaustiveness and pairwise exclusiveness. -/ |
| 25 | axiom relationClassification (p q : GraphParam) : |
| 26 | (StrictlyBounds p q ∨ StrictlyBounds q p ∨ Equivalent p q ∨ Incomparable p q) ∧ |
| 27 | ¬ (StrictlyBounds p q ∧ StrictlyBounds q p) ∧ |
| 28 | ¬ (StrictlyBounds p q ∧ Equivalent p q) ∧ |
| 29 | ¬ (StrictlyBounds p q ∧ Incomparable p q) ∧ |
| 30 | ¬ (StrictlyBounds q p ∧ Equivalent p q) ∧ |
| 31 | ¬ (StrictlyBounds q p ∧ Incomparable p q) ∧ |
| 32 | ¬ (Equivalent p q ∧ Incomparable p q) |
| 33 | |
| 34 | end Lax825442.RelationClassification |
| 35 | |
| 36 |
Used by
none
From Mathlib
none
Discussion
Ask a question or add context. Endorsements and structured flags are kept in the review panel above.
0 comments