@article{Lisovik:2003aa,
    Abstract = {The classes of functions IGF and IGF0 are investigated that can be computed by means of special index grammars. The class IGF0 is demonstrated to coincide with the class of strictly increasing functions (of a natural argument), which can be represented by systems of linear recurrence relations with natural coefficients, and to be closed with respect to the operations of addition, multiplication, series summation, and addition of a natural number to their arguments or results.},
    Author = {Lisovik, L. P. and Karnaukh, T. A.},
    Date = {2003/01/01},
    File = {A Class of Functions Computable by Index Grammars - lisovik2003 - a.pdf},
    ISBN = {1573-8337},
    Journal = {Cybernetics and Systems Analysis},
    Number = {1},
    Pages = {91--96},
    Title = {A Class of Functions Computable by Index Grammars},
    URL = {https://doi.org/10.1023/A:1023877210866},
    Volume = {39},
    Year = {2003},
    bdsk-url-1 = {https://doi.org/10.1023/A:1023877210866},
    date-added = {2023-03-13 08:01:37 +0100},
    date-modified = {2023-03-13 08:01:38 +0100},
    id = {Lisovik2003},
    doi = {10.1023/A:1023877210866}
}

@article{Lisovik:2003aa, Abstract = {The classes of functions IGF and IGF0 are investigated that can be computed by means of special index grammars. The class IGF0 is demonstrated to coincide with the class of strictly increasing functions (of a natural argument), which can be represented by systems of linear recurrence relations with natural coefficients, and to be closed with respect to the operations of addition, multiplication, series summation, and addition of a natural number to their arguments or results.}, Author = {Lisovik, L. P. and Karnaukh, T. A.}, Date = {2003/01/01}, File = {A Class of Functions Computable by Index Grammars - lisovik2003 - a.pdf}, ISBN = {1573-8337}, Journal = {Cybernetics and Systems Analysis}, Number = {1}, Pages = {91--96}, Title = {A Class of Functions Computable by Index Grammars}, URL = {https://doi.org/10.1023/A:1023877210866}, Volume = {39}, Year = {2003}, bdsk-url-1 = {https://doi.org/10.1023/A:1023877210866}, date-added = {2023-03-13 08:01:37 +0100}, date-modified = {2023-03-13 08:01:38 +0100}, id = {Lisovik2003}, doi = {10.1023/A:1023877210866} }