Welcome to the website for IFL 2019, the 31st Symposium on Implementation and Application of Functional Languages. The goal of the IFL symposia is to bring together researchers actively engaged in the implementation and application of functional and function-based programming languages. IFL 2019 will be a venue for researchers to present and discuss new ideas and concepts, work in progress, and publication-ripe results related to the implementation and application of functional languages and function-based programming.

Keynote Speaker

Olivier Danvy, Yale-NUS College

On Functional Programming and Proving

"Functional Programming and Proving" is the name of a 3000-level module in the major "Mathematics, Computation, and Statistics" at Yale-NUS College, which is the first college of liberal arts and sciences founded in Asia. This module builds on the articulatedness dispensed in the core curriculum and contributes to the inter-disciplinarity of the major by connecting programming and proving using the Coq proof assistant. It introduces the concepts of writing proofs rigorously in a domain-specific language and of reasoning about programs in this language, stating each property not just in a fleeting comment or as a show-stopping run-time assertion, but as a theorem. Learning goals include writing programs, stating properties of these programs (including unit tests), and proving these properties (including the soundness of these unit tests). In the course of the semester, the students firm up and unify their understanding of programming and of proving, appear secure enough in their knowledge in that they can explain what they do, and then, with a new awareness of the physicality of proofs (for the mathematically inclined) and of the logicality of programs (for the computationally inclined), they display eagerness to pursue their educational path in mathematics, computation, and statistics.

Against this backdrop, this talk addresses the concept of understandability in programming and in proving, namely to which extent do we understand a program and a proof, and to which extent does this understanding matter. For example, in the early days of the programming language ML at Edinburgh, types were inferred with a theorem prover. Today, little do we care why precisely our program has a type: what matters is that it does, so that we can move on, heedless of the uniqueness of this type. So where do we draw the line about understanding enough and how do we construct such an understanding in a way that is sound enough? A proof assistant such as Coq provides a remarkably firm point on which budding mathematicians and computer scientists can stand to lift their world during their formative years in college. In this day and age where applied research is all the rage, being articulate and having a degree of fluency in both programming and proving (to say nothing of statistics) means that one knows something basic that one can then apply broadly and in a sustainable way.

Olivier Danvy is currently a professor in the Science Division of Yale-NUS College and a honorary professor in the Department of Computer Science at Aarhus University. He is interested in all aspects of programming languages, from their logic and semantics to their implementation, including programming, transforming programs, program transformations, and reasoning about programs and about program transformations (for after all one man's program is another program's data). In his spare time, he wonders about Platonism: do we invent, e.g., programs, program transformers, abstract machines, and control operators, or do we discover them? Less seriously, he also hopes to formalize, one day, the chicken-and-egg problem in Coq.


The 31st IFL is organized by the National University of Singapore. Singapore is located in the heart of South-East Asia, and the city itself is extremely well connected by trains and taxis.

Park Avenue Hotel is offering special IFL'19 rates, which include transfer to the conference. The special rate for a Superior room are SGD 170 per night and the special rate for a suite is SGD 215 per night. Participants will have the option to book the hotel with the special rates after succesful registration.

Important Dates -- Time Zone: AoE (UTC-12h)

Submission of regular papers: 31st May 2019 (Friday)
15th June 2019 (Saturday)
Submission of draft papers: 15th July 2019 (Monday)
1st August 2019 (Thursday)
Regular papers notification: 1st August 2019 (Thursday)
Draft papers notification: 7th August 2019 (Wednesday)
Deadline for early registration: 15th August 2019 (Thursday)
31st Augst 2019 (Saturday)
Submission of pre-proceedings version: 15th September 2019 (Sunday)
IFL 2019 Symposium: 25th September 2019 - 27th September 2019 (Wednesday - Friday incl.)
Submission of papers for post-proceedings: 30th November 2019 (Saturday)
Notification of acceptance for post-symposium proceedings: 31st January 2020 (Friday)
Camera-ready version: 29th February 2020 (Saturday)

Submission Details

Prospective authors are encouraged to submit full papers and draft papers. All contributions must be written in English. Papers must adhere to the standard ACM SIGCONF (sigconf) two columns conference format, which can be found at Specifically, you must use the `sigconf` option of the `acmart` package, which can be included in LaTeX with the following:

\acmConference[IFL'19]{International Symposium on Implementation and Application of Functional Languages}{September 2019}{Singapore}

For pre- and post-symposium full paper submissions, the limit is firm and is 12 pages. Draft papers submissions are roughly between 8 and 15 pages.

Submissions are now closed.

Clarification of IFL 2019's Submission Process
(Notice the process has changed w.r.t. previous years)

IFL 2019 solicits two kinds of submissions:

  1. Draft papers for presentations ('weak' limit between 8 and 15 pages)
  2. Regular papers (12 pages including references)
Prior to the symposium:

Draft papers will be screened to make sure that they are within the scope of IFL, and will be accepted for presentation or rejected accordingly.

Regular papers will undergo a rigorous review by the program committee, and will be evaluated according to their correctness, novelty, originality, relevance, significance, and clarity. These papers will receive one of five verdicts:

After the symposium:

Papers accepted in their current form and those that are accepted with minor revisions will be checked to see if they are fit for publication. For papers with minor revisions this includes a check to determine whether revisions have been made. This is a light-weight process and does not involve a second formal review round.

Papers with major revisions will get published if and only if the shepherd is satisfied with the modifications.

Draft papers (both draft submissions and full papers with a draft accept status) go through a formal review round. These papers can get any of the following statuses, of which the definition has been provided above:

At no time may work submitted to IFL be simultaneously submitted to other venues; submissions must adhere to ACM SIGPLAN's republication policy:

Conference Schedule

The main conference will be held in the Executive Classroom, COM 2 level 4. The tea and lunch breaks will be held in the Multi-Purpose Room, also in COM 2 Level 4.

Day 1: Wednesday 25 September

Day 2: Thursday 26 September

Day 3: Friday 27 September

Download Draft Proceedings


Photos on Google Photos
Photos on Facebook

Registration Details

There are four categories of conference tickets. The ticket price is in SGD, but for convenience, approximations of the price in other currencies are included as well.

Early bird (student) SGD 295 (~ 195 EUR, 220 USD, 1700 HKD, 23500 JPY)
Early bird (non-student) SGD 395 (~ 260 EUR, 290 USD, 2300 HKD, 31500 JPY)
Regular ticket (student) SGD 395 (~ 260 EUR, 290 USD, 2300 HKD, 31500 JPY)
Regular ticket (non-student) SGD 495 (~ 325 EUR, 365 USD, 2900 HKD, 39500 JPY)

Registration includes participation in the symposium, the social program and conference dinner, and coffee breaks.

Program Committee

Excursion and Banquet

This IFL's excursion will take participants to the famous Gardens by the Bay, after which a Singapore-style dinner will be served at a nearby restaurant. Additional excursion and dinner tickets are availible for partners for SGD 110.

Local Information


For participants staying at the Park Rochester hotel, the hotel is generously providing a shuttle bus service to the conference. On the first day, this shuttle bus will leave at 8am from the hotel. On the other two days, the bus will leave at 9am.

Taxis and ride-share options are widely available in Singapore. The ComfortDelGro app can be used to book a taxi, while Grab and Gojek can be used for ride-sharing. Uber is not available in Singapore. These apps are somtimes aware of the exact building where the conference is being held (COM 2). Alternatively, they accept the address as destination: 15 Computing Dr, Singapore 117418. Booking rides through the various apps allows payment with credit card. Taxis in particular also accept cash. Some taxis in Singapore only accept cash, so it is recommended to always bring some cash along.

Suggestions for public transportation can be provided by apps such as Google Maps or Citymapper. To use public transportation, purchasing an MRT card is required. This can typically be done at the airport or the bigger MRT stations.


Pre-paid SIM cards are widely available at the airport and in town. Should you not wish to purchase a local SIM card, Singapore is covered by plenty of free hotspots, such as Wireless@SG.

The NUS campus has Eduroam coverage for those with an Eduroam account. For participants who don't have an Eduroam account, wireless network details will be made available during the conference.

Steering Committee

The list of Steering Committee members

Organizing Committee

Jurriën Stutterheim, Standard Chartered Bank Singapore
Wei Ngan Chin, National University of Singapore
Please direct any questions you may have towards

Previous IFL Editions


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