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: (tentative) 30th November 2019 (Saturday)
Notification of acceptance for post-symposium proceedings: (tentative) 31st January 2020 (Friday)
Camera-ready version: (tentative) 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. Regular papers (12 pages including references)
  2. Draft papers for presentations ('weak' limit between 8 and 15 pages)

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. A set of regular papers will be either accepted as-is or conditionally accepted for publication. Authors of accepted papers will be provided with committee reviews. Conditionally accepted papers will be accompanied by a set of mandatory revisions. Regular papers not accepted for publication may be considered as draft papers, at the request of the author.

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.

Prior to the symposium:

Authors of (conditionally) accepted papers and accepted presentations will submit a pre-proceedings version of their work that will appear in the draft proceedings distributed at the symposium. The draft proceedings does not constitute a formal publication. We require that at least one of the authors present the work at IFL 2019.

After the symposium:
Authors of conditionally accepted papers will submit a revised versions of their paper for the formal post-proceedings. The program committee will assess whether the mandatory revisions have been adequately addressed by the authors and thereby determines the final accept/reject status of the paper.
Our interest is to ultimately accept all conditionally accepted papers. If you are an author of a conditionally accepted paper, please make sure that you address all the concerns of the reviewers.

Authors of accepted draft papers for presentation will be given the opportunity to incorporate the feedback from discussions at the symposium and will be invited to submit a revised full article for the formal post-proceedings. The program committee will evaluate these submissions according to their correctness, novelty, originality, relevance, significance, and clarity, and will thereby determine whether the paper is accepted or rejected.

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

Day 1: Wednesday 25 September

Day 2: Thursday 26 September

Day 3: Friday 27 September

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.

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


In Cooperation With