8. An apparatus for identifying patterns in text using structures defining types of patterns which are to be identified, wherein a structure comprises one or more definition items, the apparatus comprising: a processing system coupled to memory; means for assigning a fixed weighting to each structure and each definition item in each structure, each fixed weighting being an integer multiple of the same integer; means for searching the text for a pattern to be identified on the basis of a particular structure, a pattern being provisionally identified if it matches the definition given by said particular structure; in a provisionally identified pattern, means for determining definition items making up said particular structure that have been identified in the provisionally identified pattern; means for combining the fixed weightings of the determined definition items and the fixed weighting of the particular structure to a single quantity; means for assessing whether the single quantity fulfils a given condition; and depending on the result of said assessment, means for rejecting or confirming the provisionally identified pattern.
8. An apparatus for identifying patterns in text using structures defining types of patterns which are to be identified, wherein a structure comprises one or more definition items, the apparatus comprising: a processing system coupled to memory; means for assigning a fixed weighting to each structure and each definition item in each structure, each fixed weighting being an integer multiple of the same integer; means for searching the text for a pattern to be identified on the basis of a particular structure, a pattern being provisionally identified if it matches the definition given by said particular structure; in a provisionally identified pattern, means for determining definition items making up said particular structure that have been identified in the provisionally identified pattern; means for combining the fixed weightings of the determined definition items and the fixed weighting of the particular structure to a single quantity; means for assessing whether the single quantity fulfils a given condition; and depending on the result of said assessment, means for rejecting or confirming the provisionally identified pattern. 11. The apparatus of claim 8 , wherein the arithmetic operation is a summation over all fixed weightings, the single quantity being the sum of all the weightings.