Abstract: A computer-implemented incremental algorithm for updating globally optimized linebreaks for a paragraph following a change to that paragraph takes advantage of the fact that in many cases, the effect of a change on a paragraph is of only limited extent in the paragraph. As a result, in many cases, previously evaluated information concerning feasible breakpoints for the original paragraph can be used to obtain the optimal break for the changed paragraph. The computer-implemented incremental algorithm models the paragraph as an acyclic graph and identifies those portions of the graph that are unchanged as a result of the revision. The method then evaluates feasible breakpoints and combined these with feasible breakpoints obtained from the original paragraph. Using these breakpoints, the incremental algorithm uses dynamic programming to obtain the optimal break for the changed paragraph.

Abstract: A method and apparatus are provided for converting a first document to a second document. The first document is in a first extended attribute grammar, while the second document is in a second extended attribute grammar. An extended attribute coupling grammar couples the first and second extended attribute grammars. The first document is converted to a first tree, which is partially copied to a first copy. The first copy is completed by evaluating it's attribute with respect to the extended attribute coupling grammar. The first copy is then a partially attributed tree of the second document. The partially attributed tree is completed to form a second tree based on the second extended attribute grammar. The second tree is then converted to the second document.

Abstract: A method and apparatus are provided for specifying layout processing of logically structured documents, that is, specific logical structures, in computer document handling systems. The method and apparatus allow the specification of the generic logical structure of the structured document in terms of relational attribute grammars. According to the invention, these relational attributes have a binary relationship. The generic layout structure for a class of structural documents is also represented in terms of relational attribute grammars. Coordination grammars, also represented in terms of relational attribute grammars, link the elements of the generic logical structure to the generic layout structure. By coordinating the generic layout and generic logical structures, many solutions are available. Preferential specifications are developed to resolve any potential ambiguities between the many solutions, and to select a preferred solution.