1. Introduction
1. There should be a DisplayManager who can play games with Boxes, e.g. to support the "Discrete Fisheye views", i.e. magnifier. Trick will be to make this domain-independent. Note that this all should be independent of a particular window system; window management is the task of the CaminoReal user interface, not the MathEditor.
3. All editors should be able to generate a display inside a given box, using scale to fit, or clip, or close up, or some combination thereof. Prerequisite to ability to edit math in place in a Tioga doc.
Given this activity, certain ops in an editor may only be available if display meets certain requirements, e.g. ops to modify a selected term of a polynomial can't be available if you don't have enough space to display that term. Unless you have other ways of setting the selection than hitting it with the mouse, e.g. a TermSelect <integer> operation.