The three endpoint/penultimate Delta families #
This completes part (2) of paper Corollary 2.25 for the marking consisting of the common left endpoint and the penultimate point of one strand.
theorem
Bananas.rankDelta_oneOff_rightEndpoint_family
{g : ℕ}
(B : Banana g)
(alpha : Fin (g + 1))
(a : ℕ)
(ha : 0 < a)
(hag : a ≤ g)
(hLength : 1 < B.length alpha)
:
rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (leftEndpoint B)
(strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩))
(a • oneChip (rightEndpoint B)) = 1
Corollary 2.25(2), first family: a positive right-endpoint multiple up to the genus has marked second difference one.
theorem
Bananas.rankDelta_oneOff_balanced_interior_family
{g : ℕ}
(B : Banana g)
(alpha : Fin (g + 1))
(b r : ℕ)
(hg : 0 < g)
(hb : b ≤ g - 1)
(hLength : 1 < B.length alpha)
(hrLo : 1 ≤ r)
(hrHi : r + 1 < B.length alpha)
:
rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (leftEndpoint B)
(strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩))
(↑b • oneChip (leftEndpoint B) + ↑b • oneChip (rightEndpoint B) + oneChip (strandVertex B alpha ⟨r, ⋯⟩)) = 1
Corollary 2.25(2), second family.
theorem
Bananas.rankDelta_oneOff_terminal_family
{g : ℕ}
(B : Banana g)
(alpha : Fin (g + 1))
(a b : ℕ)
(hba : b < a)
(hag : a ≤ g)
(hLength : 1 < B.length alpha)
:
rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (leftEndpoint B)
(strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩))
(↑a • oneChip (leftEndpoint B) + ↑b • oneChip (rightEndpoint B) + oneChip (strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩)) = if a = g then 1 else 0
Corollary 2.25(2), third family. A terminal chip contributes the extra
corner exactly at the boundary a = g.
theorem
Bananas.rankDelta_oneOff_three_families
{g : ℕ}
(B : Banana g)
(alpha : Fin (g + 1))
(a b r : ℕ)
(hba : b < a)
(hag : a ≤ g)
(hLength : 1 < B.length alpha)
(hrLo : 1 ≤ r)
(hrHi : r + 1 < B.length alpha)
:
rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (leftEndpoint B)
(strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩))
(a • oneChip (rightEndpoint B)) = 1 ∧ rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (leftEndpoint B)
(strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩))
(↑b • oneChip (leftEndpoint B) + ↑b • oneChip (rightEndpoint B) + oneChip (strandVertex B alpha ⟨r, ⋯⟩)) = 1 ∧ rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (leftEndpoint B)
(strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩))
(↑a • oneChip (leftEndpoint B) + ↑b • oneChip (rightEndpoint B) + oneChip (strandVertex B alpha ⟨B.length alpha - 1, ⋯⟩)) = if a = g then 1 else 0
Corollary 2.25(2), packaged with the paper's common hypotheses
0 ≤ b < a ≤ g and 0 < r < n_alpha - 1.