  The paper suggests a frequency criterion of error-free recoverability of a
missing value for sequences, i.e. discrete time processes, in a pathwise
setting without probabilistic assumptions. The paper establishes error-free
recoverability for classes of square-summable sequences with Z-transform
vanishing at isolated points with a mild rate; the case of non-summable
sequences is not excluded. The transfer functions for recovering algorithm are
presented explicitly.
  Some robustness with respect to noise contamination is established for the
suggested recovering algorithm.
