1. A method of transforming a source document, cast in a first editable form which includes a plurality of input items therein, to a target document of a second editable form which includes output items compatible therewith, said method comprising the steps of: (a) determining a set of key state variables, from amongst all possible key state variables, that reflect and collectively identify information concerning the presence of source document control items that are read in a sequence thereof from said source document; (b) determining criteria for compatibility of source input items to be read with source controls that have been read in a sequence and reflected in said key state variables; (c) establishing a fixed order for all possible output items in which any necessary pair of output items in the transformation of a given input sequence will be written in said established order; (d) defining a set of rules for each possible output item that determine whether each of said possible output items is to be written out to said target document as a function of the status of said state variables; and (e) reading a sequence of input items from said source document in accordance with said compatibility criteria; and (f) writing out all eligible output items under said rules as a transform of said sequence in said fixed order of output items.