Аn Extension theorem: Hamming isometries between linear codes over a finite quasi-Frobenius module with commutative coefficient ring extend to monomial transformation is proved. Extension theorem for other isometries is studing. The main technique involves combinatorial theory methods.
Main publications:
Igor Kheifets. Teorema o prodolzhenii izometrii lineniykh kodov nad kvazifrobeniusovymi modulyami // Fundamentalnaya i prikladnaya matematika, v pechati.