James R. Wilcox

PhD Student, UW CSE


Office: CSE2 (Gates) 252

My Calendar

I am a sixth (and final!) year PhD student interested in programming languages and applications of PL techniques to systems. I'm also a sucker for math, music, and puzzles.

I'm advised by Zach Tatlock in the PLSE group, and I'm grateful to be supported by a National Science Foundation Graduate Research Fellowship.


April 16, 2019.
Our paper on inferring inductive invariants using "phases" has been accepted to CAV '19! A preprint will appear here soon.

October 23, 2018.
I am excited to travel to Boston this week to speak at New England Systems Verification Day. I will demo a new tool that can synthesize inductive invariants for distributed systems.

September 20, 2018.
I'm on my way to St. Louis to attend ICFP and Strange Loop. Chandra will present our paper on PL techniques for 3D printing.

June 14, 2018.
Next week I'll be in Philadelphia attending PLDI. My coauthor Marcelo Taube will present our paper on using modularity to scale decidable fragments of first-order logic to verifying implementations of distributed systems.

May 16, 2018.
Our paper on programming languages techniques for 3D printing was (conditionally) accepted to ICFP 2018! Preprint forthcoming.

April 16, 2018.
I have created a list of books I keep in my office. Let me know if you'd like to borrow any!

April 16, 2018.
Our PLDI '18 paper on using modularity to bring decidable reasoning to distributed systems implementations is now available as a preprint. Check it out!

About Me

I am a sixth year PhD student in the PLSE group at UW CSE, where I am advised by Zach Tatlock. My research interests are in programming languages, systems, and formal methods. My thesis work is on compositional techniques for verifying distributed systems implementations. I generally enjoy working with proof assistants and SMT solvers on applications to all kinds of concurrent programming. I also dabble in floating point, compilers, and 3D printing.

Before coming to grad school, I graduated from Williams College in 2013, where I worked with with Steve Freund on dynamic race detection. Since then Steve and I have continued to collaborate, including on an "our powers combined" paper on verified dynamic race detection with Cormac Flanagan.

Outside computer science, I enjoy coffee, music, bicycling, and reading. My favorite Seattle coffee shops these days are Vivace in Capitol Hill and Allegro in the U district. The PLSE lab comes in a close third.

I sing baritone in the St. Mark's Cathedral Choir, Evensong Choir, and Compline Choir. In July 2018, the Evensong Choir had the pleasure of singing in residence in the UK for two weeks at Ely Cathedral and St. Paul's Cathedral, London. The Compline Choir performs each Sunday night at 9:30pm at St. Marks. The compline service a 30 minute chanted/sung service that tends to draw hundreds of people every week and thousands via a live radio broadcast and the podcast. It's a classic Seattle experience. You should check it out! You can listen live on King FM or get the podcast.

I occasionally play handbells.

Finally, I like to ride my bike (a Trek 520): in 2009 I biked the TransAm. I'm always thinking about my next tour.

Publications DBLP Google Scholar



February 21, 2017.
Exercises on Generalizing the Induction Hypothesis.
This post collects several Coq exercises on generalizing the induction hypothesis.

January 9, 2017.
A Port of the Proof of Peterson's Algorithm to Dafny.
This code-only post is a port of the proof of Peterson's Algorithm to Dafny. It also serves as a good example of how to reason about concurrent systems in Dafny, essentially by writing a thread scheduler.

April 24, 2016.
How to build a simple system in Verdi.
In this long-awaited post, we'll show how to implement and verify a simple distributed system using network semantics.

May 8, 2015
A Proof of Peterson's Algorithm.
In this post, we take a break from distributed systems to look at shared memory systems. As a case study, we give a proof that Peterson's algorithm provides mutual exclusion.

April 16, 2015
Network Semantics for Verifying Distributed Systems.
This is the first post in a series on Verdi. In this post, we'll get our feet wet by defining a formal model of how distributed systems execute on the network.

October 20, 2014
Reasoning about Cardinalities of Sums and Products.
In this short, code-heavy post, we extend some of the work from a previous post to reason about the cardinalities of sums and products.

September 14, 2014
Dependent Case Analysis in Coq without Axioms.
This post shows how to get around the limitations of the destruct tactic when doing case analysis on dependent types, without resorting to the dependent destruction tactic, which relies on additional axioms.

September 4, 2014
"run" + "time" = ???.
This brief post records Mike's description of the three ways of combining the words "run" and "time" in computer science writing.

June 12, 2014
"More Sums than Differences" Sets, Part 2: Counting MSTD Sets.
This is the (much delayed) second post in a series on More Sums than Difference Sets. In this post, we'll take a first crack at the question, "How many MSTD sets are there?" To do so, we'll write a straightforward C program that counts MSTD sets. Then we'll run it to count MSTD sets and benchmark its performance.

April 10, 2014
Tail Recursion Modulo cons.
Tail recursion has come up in a few conversations this week. This post explores a generalization of tail call optimization that I wasn't aware of until Doug described it to me.

March 3, 2014
"More Sums than Differences" Sets, Part 1: A puzzle.
This is the first post in a series on "More Sums than Differences" Sets. In this post, we'll get our terminology straight and ask a lot of questions.

December 31, 2013
Easy access to the off-campus proxy.
I use the UW proxy to access the ACM digital library from off campus, but it's annoying to type the proxy URL every time I click a link to a new paper. Here are two ways to make life easier.


I've had the pleasure of working with the following undergraduates at UW:

If you're a UW undergrad who's interested in getting involved in research, please send me an email!


In winter 2017, I taught CSE 341 (Programming Languages). Check out the course webpage!

In fall 2013, I TAed CSE 505: Programming Languages with Zach Tatlock.

I have helped run the following reading groups at UW:


I like books. I am guilty of being somewhat more of a collector than a reader, but I don't let that get me down.

I currently have around 120 technical books in my office (listed behind that link). I have another 150 or so technical books at home that are not-so-related to my research, and another 50 or so non-technical books as well. Someday, I'll list them all here.

I am happy to lend books to anyone interested. Just let me know!

I am also very happy to receive recommendations of good books that I'm missing!

© James R. Wilcox. Last updated: January 2019.