@article{Henckell:JPAA:1988,
    Abstract = {The research in this paper is motivated by the open question: ``Is the complexity of a finite semigroup S decidable?'' Following the lead of the Presentation Lemma (Rhodes), we describe the finest cover on S that can be computed using an aperiodic semigroup and give an explicit relation. The central idea of the proof is that an aperiodic computation can be described by a new `blow-up operator' H{$\omega$}. The proof also relies on the Rhodes expansion of S and on Zeiger coding.},
    Author = {Henckell, Karsten},
    File = {Pointlike sets the finest aperiodic cover of a finite semigroup - Henckell (0) (0) (0) - a - a - k.pdf},
    ISSN = {0022-4049},
    Journal = {J. Pure Appl. Algebra},
    Number = {1},
    Pages = {85--126},
    Title = {Pointlike sets: the finest aperiodic cover of a finite semigroup},
    URL = {http://www.sciencedirect.com/science/article/pii/0022404988900424},
    Volume = {55},
    Year = {1988},
    bdsk-url-1 = {http://www.sciencedirect.com/science/article/pii/0022404988900424},
    bdsk-url-2 = {http://dx.doi.org/10.1016/0022-4049(88)90042-4},
    date-added = {2016-01-29 17:53:04 +0000},
    date-modified = {2016-01-29 17:54:19 +0000},
    doi = {10.1016/0022-4049(88)90042-4}
}

@article{Henckell:JPAA:1988, Abstract = {The research in this paper is motivated by the open question: `Is the complexity of a finite semigroup S decidable?'' Following the lead of the Presentation Lemma (Rhodes), we describe the finest cover on S that can be computed using an aperiodic semigroup and give an explicit relation. The central idea of the proof is that an aperiodic computation can be described by a newblow-up operator' H{$\omega$}. The proof also relies on the Rhodes expansion of S and on Zeiger coding.}, Author = {Henckell, Karsten}, File = {Pointlike sets the finest aperiodic cover of a finite semigroup - Henckell (0) (0) (0) - a - a - k.pdf}, ISSN = {0022-4049}, Journal = {J. Pure Appl. Algebra}, Number = {1}, Pages = {85--126}, Title = {Pointlike sets: the finest aperiodic cover of a finite semigroup}, URL = {http://www.sciencedirect.com/science/article/pii/0022404988900424}, Volume = {55}, Year = {1988}, bdsk-url-1 = {http://www.sciencedirect.com/science/article/pii/0022404988900424}, bdsk-url-2 = {http://dx.doi.org/10.1016/0022-4049(88)90042-4}, date-added = {2016-01-29 17:53:04 +0000}, date-modified = {2016-01-29 17:54:19 +0000}, doi = {10.1016/0022-4049(88)90042-4} }