Fuente: Wipo "digitalization" Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for processing handwritten user instructions submitted to by a user to generate and modify digital content items. According to one aspect, there is provided a method comprising: receiving input data characterizing a document displayed on a device, the input data comprising data characterizing a plurality of handwritten strokes; generating, from the input data, a hierarchical representation of the document that characterizes relationships between objects represented by respective subsets of the plurality of handwritten strokes, wherein the hierarchical representation follows a particular hierarchical representation format; and processing the hierarchical representation of the document to identify a set of one or more candidate modifications to the document, wherein each candidate modification comprises one or more actions to change the document.