English

Almost optimal Boolean matrix multiplication [BMM]-by multi-encoding of rows and columns

Combinatorics 2018-08-27 v2 Data Structures and Algorithms

Abstract

The Boolean product R=PQR = P \cdot Q of two {0,1}  m×m  \{ 0, 1\} \; m \times m \; matrices is R(j,k)=1   IF for some   t  P(j,t)=Q(t,k)=1    ELSE R(j,k)=0.R(j,k) = 1 \; \mathrm{\ IF\ for\ some\ } \; t \; \,P(j, t) = Q(t, k) = 1\; \; \mathrm{ELSE\ } \, R(j, k) = 0. The near-optimal design reduces the complexity of computing RR from the standard m3m^3 to O(m(2+e))O(m^{(2+e)}), for arbitrary small e>0e > 0, by a practical algorithm. This renders reduced complexity to several graph-property tests: Finding triangles and higher-size cliques; finding all-pairs shortest paths, and more. Also, parsing a string ww by a context-free grammar is reduced to near quadratic in ww-size. The design uses several distinct 2-digit encodings: jj by (j1,j2),  k(j_1, j_2), \; k \, by (k1,k2)\, (k_1, k_2). Each one gives rise to bunches of short digraphs from sources jj's to sinks kk's via switching nodes, and walks between them. The combined information, using the Chinese remainder theorem, leads to the correct values of R(j,k)R(j, k).

Keywords

Cite

@article{arxiv.1806.08974,
  title  = {Almost optimal Boolean matrix multiplication [BMM]-by multi-encoding of rows and columns},
  author = {Eli Shamir},
  journal= {arXiv preprint arXiv:1806.08974},
  year   = {2018}
}

Comments

Proof is erroneous

R2 v1 2026-06-23T02:39:20.890Z