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The information in the compressed file
is sufficient to reconstruct the original file without loss
of information.
This is done with the ``uncompress'' algorithm, which works
as follows:
Again, for each character ,
the predictor (sequentially) emits its output
based on the previous characters,
where the with were gained sequentially
by feeding the approximations
of the probabilities
into the inverse Huffman Coding procedure
(see e.g. [1]), or, alternatively (depending on which
coding procedure was used),
into the inverse Arithmetic Coding procedure
( e.g. [7]).
Both variants allow for correct decoding of
from .
With both variants,
to correctly decode
some character, we first need to decode all
previous characters.
Both variants are **guaranteed** to restore
the original file from the compressed file.

**Subsections**

Juergen Schmidhuber
2003-02-25