Many aspects of defect theorems
: Harju T, Karhumaki J
Publisher: ELSEVIER SCIENCE BV
: 2004
Theoretical Computer Science
THEORETICAL COMPUTER SCIENCE
: THEOR COMPUT SCI
: 324
: 1
: 35
: 54
: 20
: 0304-3975
DOI: https://doi.org/10.1016/j.tcs.2004.03.051
We give a survey and a unified presentation of the defect theorem, its generalizations and recent aspects of interest. In its basic form, the defect theorem states that if a set of n words satisfies a nontrivial relation, then these words can be expressed simultaneously as products of at most n - I words. In other words, dependency of words causes a defect effect. There does not exist just one defect theorem, but several ones depending on the restrictions that are put to the n - I words. The defect theorem is closely related to equations of words, and in this way to the compactness theorem for systems of word equations. (C) 2004 Elsevier B.V. All rights reserved.