Graded cancellation pairings and symmetric eight-atom profiles
DefinitionSP4RankNineA graded cancellation pairing is defined on an arbitrary set of atoms , integer-valued filtration and degree functions
an involutive bijection , and a Boolean source marker . Partners have opposite source markers:
Every marked source has strictly higher filtration and degree exactly one above its target:
Thus every atom belongs to exactly one oriented cancellation pair; this is actual pairing data, not an assumed numerical balance.
The bundled profiles use the eight atoms indexed by . For arbitrary integers , the five-level profile is:
| Indices | Filtration values | Integer degrees |
|---|---|---|
The other profile has four atoms at , with degrees , and four at , with degrees
The negative-level shifts encode the grading symmetry assumed by the motivating argument. Positivity and parity are hypotheses of the theorem, not restrictions imposed by these definitions.
These eight atoms model only the nonpermanent part of the motivating nine-generator profile. A central permanent generator is not encoded. No knot, homology theory, chain complex, realization, or geometric bridge is defined here.
import Mathlib
set_option autoImplicit false
/-!
# Finite graded cancellation data for the rank-nine arithmetic layer
This definition bundle describes finite graded pairings, not knot Floer
homology. The eight atoms are the acyclic part of the motivating nine-atom
profile; the central permanent atom is not part of the finite set below.
-/
namespace SP4RankNine
/-- Every atom has a unique partner. Sources strictly decrease filtration
and have integer degree exactly one above their targets. -/
structure CancellationPairing {α : Type*} (A M : α → ℤ) where
mate : α ≃ α
involutive : Function.Involutive mate
source : α → Bool
exchange : ∀ i, source (mate i) = !(source i)
lower : ∀ i, source i = true → A (mate i) < A i
degree : ∀ i, source i = true → M i = M (mate i) + 1
/-- The ordered filtration levels of the eight nonpermanent atoms in a
five-level profile, omitting the central permanent atom. -/
def fiveLevel (g h : ℤ) : Fin 8 → ℤ := ![g, g, h, h, -h, -h, -g, -g]
/-- The labels at negative filtration are shifted by twice that level,
as in the motivating conjugation relation. -/
def fiveMaslov (g h a b c d : ℤ) : Fin 8 → ℤ :=
![a, b, c, d, c - 2*h, d - 2*h, a - 2*g, b - 2*g]
/-- Four top and four bottom atoms, omitting the central permanent atom. -/
def fourFourLevel (g : ℤ) : Fin 8 → ℤ := ![g, g, g, g, -g, -g, -g, -g]
/-- The four negative-level labels are shifted from the positive-level
labels by twice the positive filtration height. -/
def fourFourMaslov (g a b c d : ℤ) : Fin 8 → ℤ :=
![a, b, c, d, a - 2*g, b - 2*g, c - 2*g, d - 2*g]
end SP4RankNine