C SC 620 Advanced Topics in Natural Language ProcessingReading ListTranslating is EU's new boom industrySlide 4Slide 5Paper 19. Montague Grammar and Machine Translation. Landsbergen, J.Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20C SC 620Advanced Topics in Natural Language ProcessingLecture 204/8Reading List•Readings in Machine Translation, Eds. Nirenburg, S. et al. MIT Press 2003.–19. Montague Grammar and Machine Translation. Landsbergen, J.–20. Dialogue Translation vs. Text Translation – Interpretation Based Approach. Tsujii, J.-I. And M. Nagao–21. Translation by Structural Correspondences. Kaplan, R. et al.–22. Pros and Cons of the Pivot and Transfer Approaches in Multilingual Machine Translation. Boitet, C.–31. A Framework of a Mechanical Translation between Japanese and English by Analogy Principle. Nagao, M.–32. A Statistical Approach to Machine Translation. Brown, P. F. et al.Translating is EU's new boom industryTranslating is EU's new boom industryTranslating is EU's new boom industryPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Year is 1985•Montague Grammar–Meaning as Higher-Order Intentional Logic–Compositional•Meaning of an expression is a function of the meaning of its parts–Close mapping between syntax and semantics–Possible-world semanticsPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.The boys are sleeping -> x (boy’(x) -> sleep’(x))Paper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Montague Grammar and Computer Applications–Strong and weak points?–Attention given to semantics•Sound semantic base is needed for determining what a correct answer or a correct translation is…–NLP Q&A–Machine Translation–Advantage over some other linguistic theories•Exactness and constructiveness•Syntax and semantics defined locally over phrase composition rules–cf. Grammar with several syntactic levels, where the semantics is defined at the deepest levelPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Montague Grammar and Computer Applications–Strong and weak points? (contd.)–Weak syntax•Incidental property of Montague’s examples–Intentional logic and possible-world semantics too complex for practical use–Purely generative framework•Syntax and semantics in parallelPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•M-grammars–Transformational power•Consists of:–Syntactic component–Morphological component–Semantic componentPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Syntactic Component–S-tree–Nodes: category + attr/val pairs–Edges: syntactic relationsPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Rules must be bidirectional to serve as input to–M-Parser–M-Generator•Termination of transformational rules guaranteed by measure condition–E.g. number of nodes in a tree must be decreasing•Surface syntax condition–Covering grammar?–S-PARSERPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Morphological Component–A-MORPH: words -> terminal S-trees–G-MORPH: terminal S-trees -> wordsPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Montague Grammar and Machine Translation–“Possible Translation” System–Assumptions•Linguistic theory can be clearly separated from the other aspects (extralinguistic information, robustness measures, etc.)•Isolated sentences only•F-PTR: source language (SL) sentence -> set of possible translations in the target language (TL)–s’ in F-PTR(s) <-> s in F-PTR(s’)•Explicit grammars for SL and TL•Correctness-preserving property of F-PTR•Common information content between source and target sentencePaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Attractive model but there are problems with Intentional Logic as an interlingua–Discrepancy between MG literature (detailed semantics for small fragment) vs. what is needed for MT (wide coverage, superficial semantics)–Doesn’t convey pragmatic and stylistic information–Subset problemPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Subset problem•Need transfer rules from IL1 to IL2Paper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Take Intentional Logic out•Or eliminate TL grammar by transfer of terms of the logical expression obtained from Syntactic AnalysisPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Isomorphic M-grammars–Each expression in one language must have (at least) one corresponding basic expression in the other language with the same meaning–Each syntactic rule in one language must have (at least) one corresponding syntactic rule in the other language with the same meaning operation–Two sentences are translations of each other if they are derived from corresponding basic expressions by application of corresponding rulesPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Isomorphic M-grammarsPaper 19. Montague Grammar and Machine Translation. Landsbergen, J.•Interlingual system–But not