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Dan Ghica
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Semantics for physicists

I once complained that my student Brendan Fong said ‘semantics’ too much. You see, I’m in a math department, but he was actually in the computer science department at Oxford: I was his informal supervisor. Theoretical computer scientists love talking about syntax versus semantics—that is, written expressions versus what those expressions actually mean, or programs versus what those programs actually do. So Brendan was very comfortable with that distinction. But I felt my other grad students, coming from a math department didn’t understand it… and he was mentioning it in practically ever other sentence.

In 1963, Bill Lawvere figured out a way to talk about syntax versus semantics that even mathematicians—well, even category theorists—could understand. It’s called ‘functorial semantics’.  The idea is that things you write are morphisms in a category X, while their meanings are morphisms in a category Y.   There's a functor F from X to Y, which sends things you write to their meanings.  This functor sends syntax to semantics!

But physicists may not enjoy this idea unless they see it at work in physics. In physics, too, the distinction is important!  But it takes a while to understand. I hope Prakash Panangaden’s talk at the start of the Simons Institute workshop on compositionality is helpful.  Check it out!

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I am looking forward to this!

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Tom Ball, Ras Bodik, +Greg Morrisett, and I are organizing a new kind of programming languages conference. We already have several excellent conferences, but they are focused on incremental bits of novelty. We want to create a new kind of venue that complements these: to present and discuss big-picture questions and long-running programs; to view progress along the long arc of a research effort. The conference is May 3-6, 2015 in lovely Asilomar (on the Pacific Coast), CA, USA.

If this sounds interesting, please: don't just +1 it, reshare it. Why? To keep costs down and retain ownership of the conference with the community, we are independent, not affiliated with any organizations. That means you are the only PR channel we have. So please do us a favor. Thanks.

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The "axiomatic" vs. the "type-theoretic" approach -- a blog post.

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* Imminent PhD studentship funding deadline *
* please contact me immediately if you are interested. *

We invite applications for PhD study at the University of Birmingham.

We are a group of (mostly) theoretical computer scientists who explore fundamental concepts in computation and programming language semantics. This often involves profound and surprising connections between different areas of computer science and mathematics. From category theory to lambda-calculus and computational effects, from   topology to constructive mathematics, from game semantics to program compilation, this is a diverse field of research that continues to provide new insight and underlying structure.

See our webpage, with links to individual researchers, here:

Information about PhD applications may be found here:

If you are considering applying, please contact any one of us. We will be very happy to discuss the opportunities available.

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Big Green Lunch in Birmingham
We’re holding the second Big Green Lunch on Saturday 7 June from 10.30am to 5pm at the beautiful Birmingham Botanical Gardens.  

There’ll be music from local bands, dance performances, games on the lawn, cookery demonstrations and green information and advice on offer. 

For sale will be ethical and fair trade goods, bedding plants and hanging baskets and of course – food!  All this at a discounted entrance price of £1 for adults.

#brum #birmingham #green
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