Abstract: A computer-operated document retrieval system includes a lexicon of words contained in system documents, and a document look-up table that relates words by unique word numbers to the documents. A word look-up table identifies sets of words with common characteristics, specifically prefix value and word length, and a character look-up table identifies whether any word contains a specified character. A target set generator accesses the word look-up table to compose a target word set with characteristics corresponding to the search string. A refining module reduces the target set by selecting a set of characters from the search string, and accessing the character look-up table to identify which target words use the character set. The character look-up table is a boolean array with one bit elements that are processed in groups whose size corresponds to the maximum bit processing count of the computer, effectively culling non-matching words simultaneously.

Abstract: An ascending numerical sequence, such as an index of word position values within a file, is variable length binary encoded, and subsequently decoded to derive the original sequence. Encoding involves obtaining certain properties of the sequence, including the first and last element values and the maximum and minimum gaps. Unless the maximum and minimum gaps are equal, each element value between the first and last element of the sequence is reduced and the reduced sequence is further encoded, all according to various rules. Reduction involves stripping the leading 0 bit's and the first 1 bit. In most other circumstances, the resulting binary value is simply stored in a bitstream. If the maximum and minimum gaps are the same then the first and last values and the minimum and maximum gaps are simply stored in a header and no body is stored as the sequence is fully defined.

Abstract: An ascending numerical sequence, such as an index of word position values within a file, is variable length binary encoded, and subsequently decoded to derive the original sequence. Encoding involves obtaining certain properties of the sequence, including the first and last element values and the maximum and minimum gaps. Unless the maximum and minimum gaps are equal, each element value between the first and last element of the sequence is reduced and the reduced sequence is further encoded, all according to various rules. Reduction involves stripping the leading 0 bit's and the first 1 bit. Further encoding involves dropping repeating leading bits and storing the resulting binary values in a body having a bitstream format if an element value has the same number of bits as the number of bits in the preceding element value.

Abstract: A computer-operated document retrieval system includes a lexicon of words contained in system documents, and a document look-up table that relates words by unique word numbers to the documents. A word look-up table identifies sets of words with common characteristics, specifically prefix value and word length, and a character look-up table identifies whether any word contains a specified character. A target set generator accesses the word look-up table to compose a target word set with characteristics corresponding to the search string. A refining module reduces the target set by selecting a set of characters from the search string, and accessing the character look-up table to identify which target words use the character set. The character look-up table is a boolean array with one bit elements that are processed in groups whose size corresponds to the maximum bit processing count of the computer, effectively culling non-matching words simultaneously.