theorem
Q2Presentation.Lifting.finite_dual
{V : Type}
[AddCommGroup V]
[Module (ZMod 2) V]
[Finite V]
:
Finite (Module.Dual (ZMod 2) V)
Duals of finite modules are finite.
theorem
Q2Presentation.Lifting.nontrivial_dual
{V : Type}
[AddCommGroup V]
[Module (ZMod 2) V]
[Nontrivial V]
:
Nontrivial (Module.Dual (ZMod 2) V)
Duals of nontrivial modules are nontrivial.
theorem
Q2Presentation.Lifting.dual_stable_inv
{Yt : BoundaryFramedTarget}
[Finite Yt.Y]
{V : Type}
[AddCommGroup V]
[Module (ZMod 2) V]
(Φ : OperatorFamily Yt V)
(y : Yt.Y)
(U : Submodule (ZMod 2) (Module.Dual (ZMod 2) V))
(hU : ∀ m ∈ U, (dualOp Φ y) m ∈ U)
(m : Module.Dual (ZMod 2) V)
:
Stability under a transported dual upgrades to its inverse via the finite-order power expression.
theorem
Q2Presentation.Lifting.dual_simple_of_simple
{Yt : BoundaryFramedTarget}
[Finite Yt.Y]
{V : Type}
[AddCommGroup V]
[Module (ZMod 2) V]
(Φ : OperatorFamily Yt V)
(q : Marking Yt.Y)
[Finite V]
(hsimple :
∀ (U : Submodule (ZMod 2) V),
(∀ m ∈ U, (Φ.op (q Gen.sigma)) m ∈ U) → (∀ m ∈ U, (Φ.op (q Gen.tau)) m ∈ U) → U = ⊥ ∨ U = ⊤)
(U : Submodule (ZMod 2) (Module.Dual (ZMod 2) V))
:
σ/τ-simplicity transports to the dual family through the coannihilator lattice.
theorem
Q2Presentation.Lifting.dual_action_nontrivial
{Yt : BoundaryFramedTarget}
[Finite Yt.Y]
{V : Type}
[AddCommGroup V]
[Module (ZMod 2) V]
(Φ : OperatorFamily Yt V)
(haction : ¬∀ (y : Yt.Y), Φ.op y = 1)
:
¬∀ (y : Yt.Y), (dualFamily Φ).op y = 1
Action nontriviality transports to the dual family.
theorem
Q2Presentation.Lifting.famRows_dual_surjective_of_simple_structured
{Yt : BoundaryFramedTarget}
[Finite Yt.Y]
{V : Type}
[AddCommGroup V]
[Module (ZMod 2) V]
(Φ : OperatorFamily Yt V)
(q : Marking Yt.Y)
[Finite V]
[Nontrivial V]
(htwo : 2 ∣ Nat.card Yt.Y)
(hx1LY : q Gen.x1 ∈ Yt.LY)
(hsimple :
∀ (U : Submodule (ZMod 2) V),
(∀ m ∈ U, (Φ.op (q Gen.sigma)) m ∈ U) → (∀ m ∈ U, (Φ.op (q Gen.tau)) m ∈ U) → U = ⊥ ∨ U = ⊤)
(haction : ¬∀ (y : Yt.Y), Φ.op y = 1)
(hdecomp : ∀ (y : Yt.Y), ∃ w ∈ Subgroup.closure {q Gen.sigma, q Gen.tau}, y * w⁻¹ ∈ Yt.LY)
(hrel : rconj (Yt.piY (q Gen.tau)) (Yt.piY (q Gen.sigma)) = Yt.piY (q Gen.tau) ^ 2)
(uv : Module.Dual (ZMod 2) V × Module.Dual (ZMod 2) V)
:
∃ (e : Gen → Module.Dual (ZMod 2) V),
(foxShadowGen (dualFamily Φ).op q e Q2Word.tameRelator, foxShadowGen (dualFamily Φ).op q e Q2Word.wildRelator) = uv
Dual rows are surjective at nontrivial σ/τ-simple structured sections — the structured simple case applies verbatim to the dual family.