1. A computer implemented method of decompressing a compressed data sequence comprising a set of k symbols and being devoid of a significant portion of a source model associated with a data sequence from which the compressed data sequence was derived, the method comprising: generating by a processor an uncompressed data sequence comprising n symbols, wherein n is greater than k, by applying by the processor to the set of k symbols of the compressed data sequence: a plurality of constraints devoid of a significant portion of the source model; and at least one rule derived from the source model.