Reader in Invisible Writings

This - Ponder Stibbons' first role on the Faculty - involved the large-scale use of Hex. The thinking machine in the High Energy Magic Building was tasked with casting large numbers of Search spells (such as Weezencake's Unreliable Algorithm) virtually simultaneously (impossible for human wizards), trawling through L-space looking for fragments of written material. This way Hex can read any book ever written, any book that will be written at some point and books that were planned for writing that were not, as well as any book that could possibly be written. It took a huge amount of time and effort, but it was a success, proving that Ponder was indeed a Wizard worth the meals on offer at Unseen University.

"The thaumic mathematics are complex, but boil down to the fact that all books, everywhere, affect all other books." From there the nature of bi-directionalism is revealed to demonstrate that any book ever to be written can be found in any book not yet written. In mathematical terms, as noted in The Science of Discworld, L-Space represents a form of phase space. This made possible the study of invisible writings (also based on a similar theory to do with the infinite nature of Pi, and the ways in which, if one was to transcribe alphabetical values to the numbers of Pi, one could hypothetically find the contents of every book ever written).

One of the first books to come through as a complete entity was How to Dynamically Manage People for Dynamic Results in a Caring Empowering Way in Quite a Short Time Dynamically. Fragments of this turned up so often that Ponder was forced to believe that either it was either going to be an amazingly popular book or - possibly - that it was actually different books written almost identically.