We examine two systems that translate a selected subgraph into useful diagrams rendered in Graphviz using features of its Dot description language.
> Misapplication of Ashby's Law implies that to get any useful work done at higher levels of abstraction a designer faces relentless growth in complexity. Instead we construct useful diagrams by placing our logic within a pipeline where mere switching between what is understood and that which will be understood later can be distinguished.
The reader of a hypertext must make a similar distinction: click a link or continue reading. The authors of hypertext (the users of wiki) need not fully understand their readers in Ashby's sense in order to exert positive and useful control. And, more indirectly, the implementers of wiki need not fully understand their authors.