@article{10.1145/321466.321473,
    Abstract = {It is shown that the equivalence problem for A-free nondeterministic generalized machines is unsolvable, and it is observed that this result implies the unsolvability of the equality problem for c-finite languages.},
    Address = {New York, NY, USA},
    Author = {Griffiths, T. V.},
    File = {The unsolvability of the Equivalence Problem for {$\Lambda$}-Free nondeterministic generalized machines - 321466.321473 - a.pdf},
    ISSN = {0004-5411},
    Journal = {J. ACM},
    Month = {jul},
    Number = {3},
    Pages = {409--413},
    Publisher = {Association for Computing Machinery},
    Title = {The Unsolvability of the Equivalence Problem for {$\Lambda$}-Free Nondeterministic Generalized Machines},
    URL = {https://doi.org/10.1145/321466.321473},
    Volume = {15},
    Year = {1968},
    bdsk-url-1 = {https://doi.org/10.1145/321466.321473},
    date-added = {2023-01-17 08:52:50 +0100},
    date-modified = {2023-01-17 08:52:50 +0100},
    issue_date = {July 1968},
    numpages = {5},
    doi = {10.1145/321466.321473}
}

@article{10.1145/321466.321473, Abstract = {It is shown that the equivalence problem for A-free nondeterministic generalized machines is unsolvable, and it is observed that this result implies the unsolvability of the equality problem for c-finite languages.}, Address = {New York, NY, USA}, Author = {Griffiths, T. V.}, File = {The unsolvability of the Equivalence Problem for {$\Lambda$}-Free nondeterministic generalized machines - 321466.321473 - a.pdf}, ISSN = {0004-5411}, Journal = {J. ACM}, Month = {jul}, Number = {3}, Pages = {409--413}, Publisher = {Association for Computing Machinery}, Title = {The Unsolvability of the Equivalence Problem for {$\Lambda$}-Free Nondeterministic Generalized Machines}, URL = {https://doi.org/10.1145/321466.321473}, Volume = {15}, Year = {1968}, bdsk-url-1 = {https://doi.org/10.1145/321466.321473}, date-added = {2023-01-17 08:52:50 +0100}, date-modified = {2023-01-17 08:52:50 +0100}, issue_date = {July 1968}, numpages = {5}, doi = {10.1145/321466.321473} }