- Linking requires D = 3 (Alexander duality)
The theorem linking_requires_D3 proves that non-trivial circle linking exists only for D = 3, via the equivalence SphereAdmitsCircleLinking D ↔ D = 3 established by alexander_duality_circle_linking from reduced cohomology of S¹.
- 8-tick = 2^D forces D = 3
The theorem eight_tick_forces_D3 derives D = 3 from the identity eight_tick = 2^D together with the auxiliary result eight_tick = 2^3.
- Cl_3 spinor structure
D = 3 yields Cl_3 ≅ M₂(ℂ) with 2-component spinors (Spin(3) ≅ SU(2)), as shown by spinor_dim_D3 = 2 and the HasRSSpinorStructure predicate specialized to D = 3.
- Cited Lean anchors
The derivation rests on the theorems listed in the cited_theorems array below.