I think this sentence is one of the most overlooked key points. This virtual, and in '68 the live demo was a quantum leap in managing text and locked the attention on that level. However, the essence of this framework is managing symbols and making statements by them directly - not editing texts on pages and navigate around them. For example, seeing and managing the following statements in parallel: 1: there is an idea of "Locatable" represented by an entity. 2: "Locatable" in this environment contains X and Y attributes represented by their respective entity instances. 3: Another entity (be it a mouse pointer, a window or a car on a street) can or must be "Locatable" (among many other possible aspects). 4: "My car" entity is "Locatable" at 40, 20. We need a system that allows managing such statements and allow other systems behave according to them.