Previous Awards

The 2020 Alonzo Church Award for Outstanding Contributions to
Logic and Computation

The ACM Special Interest Group on Logic (SIGLOG), the European Association for Theoretical Computer Science (EATCS), the European Association for Computer Science Logic (EACSL), and the Kurt Gödel Society (KGS) are pleased to announce that

Ronald Fagin, Phokion G. Kolaitis, Renée J. Miller, Lucian Popa, and Wang Chiew Tan

have been selected as the winners of the 2020 Alonzo Church Award for Outstanding Contributions to Logic and Computation. The award recognizes their ground-breaking work on laying the logical foundations for data exchange, described in the following papers:

(1) Ronald Fagin, Phokion G. Kolaitis, Lucian Popa, Renée J. Miller. Data exchange: Semantics and Query Answering, Proceedings of the 9th International Conference on Database Theory (ICDT 2003), pp. 207-223, 2003.
Full journal  version: Theoretical Computer Science, Vol. 336, No. 1, pp. 89-124, 2005.

(2) Ronald Fagin, Phokion G. Kolaitis, Lucian Popa, Wang Chiew Tan. Composing Schema Mappings: Second-Order Dependencies to the Rescue, Proceedings of the 23rd ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems (PODS 2004), pp. 83-94, 2004.
Full journal version: ACM Transactions on Database Systems, Vol. 30, No. 4, pp. 994-1055, 2005.

Data exchange is the problem of transforming data structured under a schema, called the source schema, into data conforming to a different schema, called the target schema. The results and techniques developed have in addition to gaining theoretical insights influenced the development of industrial and academic tools. The 2020 Church Award was selected by a panel consisting of Mariangiola Dezani, Thomas Eiter (chair), Javier Esparza, Radha Jagadeesan and Natarajan Shankar.

THE CONTRIBUTION

Data exchange is an old and ubiquitous problem in data management that was described by Philip Bernstein as the “oldest problem in databases”. Early work on data exchange used low-level, ad hoc programs to transform data from the source schema to the target schema, which resulted into inefficiencies and limited reusability. Publications (1) and (2) laid the logical foundations for data exchange and became the catalyst for the development of data exchange as a research area in its own right. Publication (1) is about logic in computer science: a fragment of first-order logic, called source-to-target tuple-generating dependencies (in short, s-t tgds), is systematically used as a specification language in data exchange. The algorithmic and structural properties of s-t tgds are explored, and the concept of a universal solution is introduced as the preferred way to carry out the data exchange task. Publication (2) is about logic from computer science: first, it is shown that the language of s-t tgds is not closed under composition; second, a new fragment of second-order logic, called second-order tuple-generating dependencies (in short, SO tgds) is identified and shown to be the “right” logic-based specification language for composing s-t tgds. The award publications are well-cited and have been recognized with two test-of-time awards.

The 2019 Alonzo Church Award for Outstanding Contributions to
Logic and Computation

The 2019 Alonzo Church Award for Outstanding Contributions to Logic and Computation is given jointly to Murdoch J. Gabbay and Andrew M. Pitts for their ground-breaking work introducing the theory of nominal representations.

The ACM Special Interest Group on Logic (SIGLOG), the European Association for Theoretical Computer Science (EATCS), the European Association for Computer Science Logic (EACSL), and the Kurt Gödel Society (KGS) are pleased to announce that Murdoch J. Gabbay (Heriot-Watt University, UK) and Andrew M. Pitts (Cambridge University, UK) have been selected as the winners of the 2019 Alonzo Church Award for Outstanding Contributions to Logic and Computation. The award recognizes their ground-breaking work introducing the theory of nominal representations, a powerful and elegant mathematical model for computing with data involving atomic names, described in the following papers:

  • Murdoch J. Gabbay and Andrew M. Pitts. A new approach to abstract syntax with variable binding, Formal Aspects of Computing 13(3):341– 363, 2002.
  • Andrew M. Pitts. Nominal logic, a first order theory of names and binding, Information and Computation 186(2):165–193, 2003.

For the invention of nominal techniques, providing a highly in- fluential mathematical model for key concepts that arise when computing with data involving atomic names.

The 2019 Church Award was selected by a panel consisting of Thomas Eiter, Javier Esparza, Radha Jagadeesan, Catuscia Palamidessi, and Natarajan Shankar.

Description of the contribution

The 2018 Alonzo Church Award for Outstanding Contributions to
Logic and Computation

The 2018 Alonzo Church Award for Outstanding Contributions to Logic and Computation is given jointly to Tomas Feder and Moshe Y. Vardi for fundamental contributions to the computational complexity of constraint-satisfaction problems. Their contributions appeared in two papers:

1. Tomas Feder, Moshe Y. Vardi: Monotone Monadic SNP and Constraint Satisfaction. STOC 1993, 612-622.
2. Tomas Feder, Moshe Y. Vardi: The Computational Structure of Monotone Monadic SNP and Constraint Satisfaction: A Study through Datalog and Group Theory. SIAM J. Comput. 28(1), 57–104 (1998).

CONTRIBUTION SUMMARY: The Feder-Vardi project aimed at finding a large subclass of NP that exhibits a dichotomy (all problems are either in PTIME or NP-complete). The approach is to find this subclass via syntactic prescriptions. The paper identified a class of problems specified by “monotone monadic SNP without inequality”, which may exhibit this dichotomy. Feder and Vardi justified placing all three restrictions by showing, using Lad- ner’s theorem, that classes obtained by using only two of the above three restrictions do not show this dichotomy. They then explored the structure of this class. They show that all problems in this class reduce to the seemingly simpler class CSP – Constraint Satisfaction Problems. They divided CSP into subclasses and tried to unify the collection of all known polytime algorithms for CSP problems and extract properties that make CSP problems NP-hard. They conjectured that the class CSP (and therefore, also MMSNP) also satisfy the dichotomy property. This became known as the Feder-Vardi Dichotomy Conjecture. The Dichotomy Conjecture stimulated an exten- sive research program, which culminated in 2017 in two independent proofs, by A. Bulatov and by D. Zhuk, of its correctness.

Description of the contribution

The 2017 Alonzo Church Award for Outstanding Contributions to
Logic and Computation

The 2017 Alonzo Church Award for Outstanding Contributions to Logic and Computation is given jointly to Samson Abramsky, Radha Jagadeesan, Pasquale Malacaria,
Martin Hyland, Luke Ong, and Hanno Nickau for providing a fully-abstract semantics for higher-order computation through the introduction of game models, thereby fundamentally revolutionising the field of programming language semantics, and for the applied impact of these models.

Description of the contribution

The 2016 Alonzo Church Award for Outstanding Contributions to
Logic and Computation

The 2016 Alonzo Church Award for Outstanding Contributions to Logic and Computation is given to Rajeev Alur and David Dill for their invention of timed automata, a decidable model of real-time systems, which combines a novel, elegant, deep theory with widespread practical impact.

Description of the contribution