Remaining cross-one-off Delta families #
This completes the rank-difference assertions in part (3) of paper Corollary 2.25.
theorem
Bananas.rankDelta_crossOneOff_right_interior_family
{g : ℕ}
(B : Banana g)
(alpha beta : Fin (g + 1))
(p : Utilities.Certificate.SubdivisionGraph.Spec.PathPosition B alpha)
(b : ℕ)
(hg : 2 ≤ g)
(hab : alpha ≠ beta)
(hpLo : 2 ≤ ↑p)
(hpHi : ↑p < B.length alpha)
(hBeta : 2 ≤ B.length beta)
(hb : b < g)
:
rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (strandVertex B alpha ⟨1, ⋯⟩)
(strandVertex B beta ⟨B.length beta - 1, ⋯⟩))
(↑b • oneChip (rightEndpoint B) + oneChip (strandVertex B alpha p)) = 1
Corollary 2.25(3): a right-endpoint coefficient and one sufficiently interior chip on the first marked strand have second difference one.
theorem
Bananas.rankDelta_crossOneOff_two_interior_boundary_eq_zero
{g : ℕ}
(B : Banana g)
(alpha beta : Fin (g + 1))
(p : Utilities.Certificate.SubdivisionGraph.Spec.PathPosition B alpha)
(q : Utilities.Certificate.SubdivisionGraph.Spec.PathPosition B beta)
(hg : 2 ≤ g)
(hab : alpha ≠ beta)
(hpLo : 2 ≤ ↑p)
(hpHi : ↑p < B.length alpha)
(hqLo : 1 ≤ ↑q)
(hqHi : ↑q + 1 < B.length beta)
:
rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (strandVertex B alpha ⟨1, ⋯⟩)
(strandVertex B beta ⟨B.length beta - 1, ⋯⟩))
((↑g - 1) • (oneChip (leftEndpoint B) + oneChip (rightEndpoint B)) + oneChip (strandVertex B alpha p) + oneChip (strandVertex B beta q)) = 0
The two-interior family at its top coefficient. Here the first three divisors are nonspecial, while the twice-subtracted divisor remains in the banana normal-form range, and the second difference is zero.
theorem
Bananas.rankDelta_crossOneOff_terminal_delta_family
{g : ℕ}
(B : Banana g)
(alpha beta : Fin (g + 1))
(p : Utilities.Certificate.SubdivisionGraph.Spec.PathPosition B alpha)
(b : ℕ)
(hg : 2 ≤ g)
(hab : alpha ≠ beta)
(hpLo : 2 ≤ ↑p)
(hpHi : ↑p < B.length alpha)
(hBeta : 2 ≤ B.length beta)
(hb : b ≤ g - 1)
:
rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (strandVertex B alpha ⟨1, ⋯⟩)
(strandVertex B beta ⟨B.length beta - 1, ⋯⟩))
((↑g - 1) • oneChip (leftEndpoint B) + ↑b • oneChip (rightEndpoint B) + oneChip (strandVertex B alpha p) + oneChip (strandVertex B beta ⟨B.length beta - 1, ⋯⟩)) = if b < g - 1 then 1 else 0
Corollary 2.25(3), the terminal-chip delta family.
theorem
Bananas.rankDelta_crossOneOff_balanced_delta_family
{g : ℕ}
(B : Banana g)
(alpha beta : Fin (g + 1))
(p : Utilities.Certificate.SubdivisionGraph.Spec.PathPosition B alpha)
(q : Utilities.Certificate.SubdivisionGraph.Spec.PathPosition B beta)
(b : ℕ)
(hg : 2 ≤ g)
(hab : alpha ≠ beta)
(hpLo : 2 ≤ ↑p)
(hpHi : ↑p < B.length alpha)
(hqLo : 1 ≤ ↑q)
(hqHi : ↑q + 1 < B.length beta)
(hb : b ≤ g - 1)
:
rankDelta
(mark (Utilities.Certificate.SubdivisionGraph.Spec.graph B) (strandVertex B alpha ⟨1, ⋯⟩)
(strandVertex B beta ⟨B.length beta - 1, ⋯⟩))
(↑b • (oneChip (leftEndpoint B) + oneChip (rightEndpoint B)) + oneChip (strandVertex B alpha p) + oneChip (strandVertex B beta q)) = if b < g - 1 then 1 else 0
Corollary 2.25(3), the balanced two-interior delta family.