current processing model (lines -> pages) is inadequate and too limited

penalties is indirect specification and requires more experience; prefer a more direct method

need means to express relationships among objects: alignment, constrained distances, sizes as functions of other objects; frees user of low-level detail and permits automatic recalibration

need way to express constraints on appearance of objects and to have sytem choose best appearance

characteristics of documents are best described as properties of page spaces rather than properties of the objects; even three-dimensional spaces (for overlays)

need more flexible methods for specifying nesting and arrangement of page spaces (hierarchal structures, rectangular spaces); more general solutions might help with layout problems now solved by specialized programs

lack of efficient algorithms for implementing the desired functions; proved difficult to design a language to express the desired functions