A syntactic skeleton for statistical machine translation

We present a method for improving statistical machine translation performance by using linguistically motivated syntactic information. Our algorithm recursively decomposes source language sentences into syntactically simpler and shorter chunks, and recomposes their translation to form target language sentences. This improves both the word order and lexical selection of the translation. We report statistically significant relative improvementsof 3.3% BLEU score in an experiment (English!Spanish) carried out on an 800-sentence test set extracted from the Europarl corpus

F-structure transfer-based statistical machine translation

In this paper, we describe a statistical deep syntactic transfer decoder that is trained fully automatically on parsed bilingual corpora. Deep syntactic transfer rules are induced automatically from the f-structures of a LFG parsed bitext corpus by automatically aligning local f-structures, and inducing all rules consistent with the node alignment. The transfer decoder outputs the n-best TL f-structures given a SL f-structure as input by applying large numbers of transfer rules and searching for the best output using a log-linear model to combine feature scores. The decoder includes a fully integrated dependency-based tri-gram language model. We include an experimental evaluation of the decoder using different parsing disambiguation resources for the German data to provide a comparison of how the system performs with different German training and test parses

Encoding TLA+ set theory into many-sorted first-order logic

We present an encoding of Zermelo-Fraenkel set theory into many-sorted first-order logic, the input language of state-of-the-art SMT solvers. This translation is the main component of a back-end prover based on SMT solvers in the TLA+ Proof System

Meta-F*: Proof Automation with SMT, Tactics, and Metaprograms

We introduce Meta-F*, a tactics and metaprogramming framework for the F* program verifier. The main novelty of Meta-F* is allowing the use of tactics and metaprogramming to discharge assertions not solvable by SMT, or to just simplify them into well-behaved SMT fragments. Plus, Meta-F* can be used to generate verified code automatically. Meta-F* is implemented as an F* effect, which, given the powerful effect system of F*, heavily increases code reuse and even enables the lightweight verification of metaprograms. Metaprograms can be either interpreted, or compiled to efficient native code that can be dynamically loaded into the F* type-checker and can interoperate with interpreted code. Evaluation on realistic case studies shows that Meta-F* provides substantial gains in proof development, efficiency, and robustness.Comment: Full version of ESOP'19 pape

Deep syntax language models and statistical machine translation

Hierarchical Models increase the reordering capabilities of MT systems by introducing non-terminal symbols to phrases that map source language (SL) words/phrases to the correct position in the target language (TL) translation. Building translations via discontiguous TL phrases increases the difficulty of language modeling, however, introducing the need for heuristic techniques such as cube pruning (Chiang, 2005), for example. An additional possibility to aid language modeling in hierarchical systems is to use a language model that models fluency of words not using their local context in the string, as in traditional language models, but instead using the deeper context of a word. In this paper, we explore the potential of deep syntax language models providing an interesting comparison with the traditional string-based language model. We include an experimental evaluation that compares the two kinds of models independently of any MT system to investigate the possible potential of integrating a deep syntax language model into Hierarchical SMT systems

Translating Alloy to SMT-LIB

Alloy is a tool for writing specifications and constructing instances of these specifications, based on relational logic. Satisfiability Modulo Theories (SMT) solvers embody another popular approach to specification and instance-generation; most solvers implement a language based on the SMT-LIB standard. The Alloy language and the core of SMT-LIB are each formally equivalent, over finite structures, to first-order mathematical logic; however, they support quite different modeling idioms. To help bridge this gap we have initiated a project to construct a translation from Alloy to SMT-LIB