Please vote!

If you are a UK citizen, please remember to vote in the EU elections tomorrow. Latest poll results for Scotland from the Herald are above (and linked). I will vote Green.

Farage's Brexit Party is doing distressingly well. If you are considering sitting this one out, I remind you of the words of Robert Heinlein:

If you are part of a society that votes, then do so. There may be no candidates and no measures you want to vote for ... but there are certain to be ones you want to vote against. [from Time Enough for Love]

PLFA in Padova

Next week, I will teach six hours of classes based on PLFA, and deliver a departmental seminar on the same topic. Maybe I will see you there!

Seminar: 16.00-17.00 Tue 28 May (details)

Classes: 12.30-15.30 Wed-Thu 29-30 May (details)

Pinker's Thirteen Rules for Better Writing

Steven Pinker tweets thirteen rules for better writing. Spotted via Boing Boing.

1. Reverse-engineer what you read. If it feels like good writing, what makes it good? If it’s awful, why?
2. Prose is a window onto the world. Let your readers see what you are seeing by using visual, concrete language.
3. Don’t go meta. Minimize concepts about concepts, like “approach, assumption, concept, condition, context, framework, issue, level, model, perspective, process, range, role, strategy, tendency,” and “variable.”
4. Let verbs be verbs. “Appear,” not “make an appearance.”
5. Beware of the Curse of Knowledge: when you know something, it’s hard to imagine what it’s like not to know it. Minimize acronyms & technical terms. Use “for example” liberally. Show a draft around, & prepare to learn that what’s obvious to you may not be obvious to anyone else.
6. Omit needless words (Will Strunk was right about this).
7. Avoid clichés like the plague (thanks, William Safire).
8. Old information at the beginning of the sentence, new information at the end.
9. Save the heaviest for last: a complex phrase should go at the end of the sentence.
10. Prose must cohere: readers must know how each sentence is related to the preceding one. If it’s not obvious, use “that is, for example, in general, on the other hand, nevertheless, as a result, because, nonetheless,” or “despite.”
11. Revise several times with the single goal of improving the prose.
12. Read it aloud.
13. Find the best word, which is not always the fanciest word. Consult a dictionary with usage notes, and a thesaurus.

After absorbing these, read his The Sense of Style.

Two weeks of teaching in Ethiopia

I just returned from teaching a class of twenty-two women in Addis Ababa, courtesy of IOHK. Rounding off eight weeks of Haskell, taught by Lars Brünjes and Polina Vinogradova, I spent two weeks teaching IOHK's smart contract languages Plutus and Marlowe. It was an amazing experience. I thank IOHK and my students for the opportunity, and I look forward to repeating it someday.

Here is IOHK's announcement prior to the course, and an analysis from an outsider.

Thank you to my students for introducing me to injera!

With Wanda, Lars, and Polina in traditional dress at the graduation ceremony.

All the students in traditional dress for graduation. They wear it well!

Root causes

Trevor Sumner delivers an incisive analysis of the root causes of the Ethiopian airlines crash. Many call it a software failure, but he looks at a trail of issues: economic problem, airframe problem, aerodynamic problem, systems engineering problem, sensor problem, maintenance practices problem, pilot training problem, pilot expertise problem, and back to economic problem.

(Thanks to Robin Sloan for highlighting Sumner's post in his weekly newsletter, Year of the Meteor.)

Plutusfest

Plutus is the smart contract language for Cardano, the proof-of-work blockchain developed by IOHK. It is based on Haskell, and developed by a team led by Manuel Chakravarty and myself. IOHK will be premiering Plutus to the world at Plutusfest in Edinburgh, this coming Tuesday. You are invited! Details at plutusfest.io.

Brexit: Leave ‘very likely’ won EU referendum due to illegal overspending, says Oxford professor’s evidence to High Court

There's been little attention paid to the fact Vote Leave broke UK spending law. If that had happened in an election to Parliament, the vote would have been annulled and the election held again. I have to admit, despite the breach, I thought it unlikely the extra spending could actually have swung the election. But the Independent reports that Prof Philip Howard of Oxford (above) says otherwise.

[T]he Remain campaign was forced to stop its digital advertising on the last day of the June 2016 campaign because it had reached its spending limit. In contrast, Vote Leave carried on, despite busting its limit two days before the vote – and was later found by the Electoral Commission to have broken the law.

The illegal adverts were seen by millions, of whom 20--30% made up their mind in the last week, and half of those on the last day. In that context, the estimate that 800K people were swayed, more than the 635K needed to change the outcome, seems entirely plausible.

Programming Language Foundations in Agda

Wen Kokke and I are pleased to announce the availability of the textbook:

  Programming Language Foundations in Agda
  plfa.inf.ed.ac.uk
  github.com/plfa/plfa.github.io/

It is written as a literate script in Agda, and available at the above URLs. The books has so far been used for teaching at the Universities of Edinburgh and Vermont, and at Google Seattle. Please send your comments and pull requests!

The book was presented in a paper (of the same title) at the XXI Brazilian Symposium on Formal Methods, 28--30 Nov 2018, and is available here:

  http://homepages.inf.ed.ac.uk/wadler/topics/agda.html#sbmf

The paper won the SBMF 2018 Best Paper Award, 1st Place.

Co-Recursive Interview

Adam Gordon Bell interviewed me for his Co-Recursive podcast. Thanks, Adam!

Developer Yoga

My favourite is the first, Lambdasana. Spotted while at LambdUp in Prague.