Graph Lemma


Title: Graph Lemma
Authors: Štěpán Holub and Štěpán Starosta
Submission date: 2021-05-24
Abstract: Graph lemma quantifies the defect effect of a system of word equations. That is, it provides an upper bound on the rank of the system. We formalize the proof based on the decomposition of a solution into its free basis. A direct application is an alternative proof of the fact that two noncommuting words form a code.
  author  = {Štěpán Holub and Štěpán Starosta},
  title   = {Graph Lemma},
  journal = {Archive of Formal Proofs},
  month   = may,
  year    = 2021,
  note    = {\url{},
            Formal proof development},
  ISSN    = {2150-914x},
License: BSD License
Depends on: Combinatorics_Words