Abstract:
Some properties of linear difference operators whose coefficients have the form of infinite two-sided sequences over a field of characteristic zero are considered. In particular, it is found that such operators are deprived of some properties that are natural for differential operators over differential fields. In addition, we discuss questions of the decidability of certain problems arising in connection with the algorithmic representation of infinite sequences.
Key words:linear difference equations, infinite sequences in the role of coefficients, annihilating operators, solution spaces, divisibility, common multiples of operators, undecidable problems.