Method for comparing text files with differently arranged text sections in documents

A computer implemented method for systematically comparing contents of at least two digitally stored documents (Doc1, Doc2), which are stored on digital medium and which are loaded by a computer to be compared by a computer, wherein initially all areas of the stored documents (Doc1, Doc2) are unmarked, wherein the stored documents have repetitions, comprising the following steps:

• a) computing a histogram of at least one of the stored documents, and comparing the computed histogram with a reference histogram associated with a reference document, each histogram including word frequencies (f1, f2, f3 . . . ) and a group associated with each word frequency, each group corresponding to a fraction of words in each document occurring with the same word frequency, the comparing including searching for and identifying a repetition number n, wherein n is a natural number, which when multiplied by the word frequencies in the computed histogram, causes a comparison of groups in the reference histogram associated to a given word frequency (f1, f2, f3 . . . ) to match groups in the computed histogram associated to the given word frequency multiplied by n (n×f1, n×f2, n×f3 . . . ) within a predefined range;
• b) searching for identical and roots (Root1, Root2) in the unmarked areas of the documents with n occurrences, of which there are at least two, wherein the roots comprise a string of text symbols, being in particular words, word groups or other unambiguous textual formatting functions, and must only occur exactly n times in each of the documents, and wherein if a root is not unambiguous it is discarded, and wherein a search for the root is carried out in the first document in order to determine unambiguity, and then a search for the root is carried out in the second document in order to determine its unambiguity;
• c) if roots have been found, comparison of the documents, starting with the roots (Root1, Root2), until there is no longer any agreement, wherein the areas (Area1, Area2) found in this way are being marked;
• d) repeating the above steps, starting with b) in a recursion until there are no longer any unique and identical roots or until no longer any found areas can be marked, wherein the marked areas are at first not taken into account in the search for roots and areas;
• and
• e). providing a user interface that enables a user to examine positions of the marked areas (Area1, Area2) in each of the documents.