Nonzero cyclic blocks force all three mixed addresses to be supported
Provedmme_stothers_phi233_cyclic_block_supports_mixed_addressesalgebraic-complexitycyclic-symmetrizationdavie-stotherslaser-methodmatrix-multiplicationtensor-support
Consider three cyclic ambient edges selected modewise in the cyclic symmetrization of the coarse constituent. Suppose that at every tensor-power coordinate, the block determined by those three selected mode vertices is nonzero. Then each of the three cyclically mixed three-mode addresses is coordinatewise one of the ten Davie--Stothers support types. Equivalently,
This is the profile-specific compatibility condition needed to turn affine-hash vertex isolation into a direct-sum restriction of literal tensor blocks.
Preamble
import Definitions.Def_mme_stothers_phi233_cyclic_grading_address import Definitions.Def_mme_stothers_phi233_outer_grading import Theorems.Thm_mme_cyclic_triple_grading_nonzero_factors import Theorems.Thm_mme_stothers_phi233_outer_grading_support open MME universe u set_option autoImplicit false
Formal statement
theorem mme_stothers_phi233_cyclic_block_supports_mixed_addresses
{K : Type u} [Field K] (q : ℕ)
{N alpha beta gamma delta : ℕ}
(es : Fin 3 → MME.StothersFourth.Phi233.CyclicAmbientEdge
N alpha beta gamma delta)
(hblocks : ∀ j : Fin (2 * N),
(mmeCyclicTripleGrading
(MME.StothersFourth.Phi233.outerGrading K q)).blockTensor
(fun i ↦
MME.StothersFourth.Phi233.cyclicGradingAddress (es i) i j) ≠ 0) :
MME.StothersFourth.Phi233.CyclicCoordinatewiseSupported
(es 0) (es 1) (es 2) := by
sorrySource
A. M. Davie and A. J. Stothers, Improved Bound for Complexity of Matrix Multiplication (2013), cyclic support pruning in Lemma 5.1(v), pp. 366--367; https://www.maths.ed.ac.uk/~sandy/a11164.pdf