Edsger W. Dijkstra on Reasoning about Processes

To see why this video is well worth watching and listening to carefully, consider the following question.

Imagine a process which, given a list containing a number of tasks, each of which is one of two different types, call them odd or even, chooses two at random, and if they both turn out to be the same type, adds an even task to the list, otherwise it adds an odd task to the list. This process then repeats until there are fewer than two tasks on the list, at which point it returns the list of the remaining tasks as its result. How many tasks will this process produce as a result?


At 42 minutes 20 seconds on functions of a permutation, see How to Be A Genius Part II. And on the application of these ideas to determinants and solving systems of linear equations, see Charles Lutwidge Dodgson's book An Elementary Treatise on Determinants: With Their Application to Simultaneous Linear Equations.


See this for how to construct bijections on partial orders.


At 51 minutes 20 seconds, on the animistic connotations of the term "bug" ... do you often hear people at, say Google or Microsoft, saying "Another bug got into my program! We need to fumigate this fucking building, ... it's full of bugs!" ...

Now see Ben Eater on Running a Breadboard at 1MHz and watch this lecture:


Then see Patrick Cousot & Radhia Cousot. Abstract interpretation: a unified lattice model for static analysis of programs by construction or approximation of fixpoints.

This paper: Systematic design of program analysis frameworks gives a more general algorithm for lattice completion using a Galois Connection as a fixpoint operator, but the paper is not available from the link on the author's web page. This reference is from A Standard Basis for Standard Bases.


Laura Pausini on Galois Connections:


Comments

Post a Comment

Popular posts from this blog

Stefan Molyneux on Resource Based Economy

Image
This is an interesting discussion. What most people don't realise is that capitalism as we practice it now wastes 99.9% of the human and material resources we currently use. Once you realise that, the problems raised by the idea of gift or resource-based economies become much more tractable. At  10 minutes 30 seconds  the discussion turns to the way we treat our family and friends differently. We don't charge our nearest and dearest. At this point Molyneux brings in Neo-Darwinian evolution to explain why there is this difference between the way we treat our kith and kin to the way we treat everybody else. I guess he will go on to argue that this is because we evolved to be like this, otherwise we would not have survived. He will presumably say that this is human nature and because it is genetically determined, nothing we can do short of a programme of eugenics and euthenasia will change that. Well, ... you know what my answer to that will be, ... something along the lines:
Read more

Nikola Tesla and the End of The World

Image
At  1 minute 21 seconds  the building in the background, in Trafalgar Square , as she says "There is a story in our family that my great grandfather worked with Nikola Tesla, ..." is ... ... what? Hint: it is near to a statue of George Washington, a replica donated by the  Commonwealth of Virginia in 1921 .  See  War Crimes . Watch all four episodes of  Nikola Tesla and the End of The World  and then watch this: And on the meaning of the word sovereignty see: On the Mason-Dixon Line, the "boundary of slavery" in the American colonies, it might be insightful to compare the  Britannica  and  Wikipedia  entries and see where they differ. Then, especially if you're my daughter, see  On Feminist Genealogy . Then see this documentary about Mark Knopfler and what motivates his music. There's a nice bit at  17 minutes  about where songs come from, and what happens to their origin, and the role of Town Planners like my father, in this process, part
Read more

Sabine Hossenfelder - Lost in Math

Image
Sabine's book,  Lost in Math published in 2018. See  Rebecca Smethurst on the Crisis in Cosmology . Here's an interview on the subject of the book: At 16 minutes 27 seconds on aesthetics in a theory. I think you should worry first and foremost about whether or not it works, otherwise you are not doing empirical science. At 19 minutes 19 seconds on whether there would be better ways to advance physics other than by building the next generation of super high-energy particle collider. This is similar to military spending and it's really just an artefact of Keynesian monetary theory: that you can create 'wealth' by employing men to dig holes in the road and fill them up again. Of course you are not creating real wealth, you are destroying it and creating fake money. The upshot is that the better ways of spending much, much less money on encouraging sound scientific teaching and research are not of any interest, because they don't employ nearly so ma
Read more