Lambda-Calculus Representation in NLTK CCG

Question

I am trying to implement a probabilistic ccg with lambda-calculus features.

Basically i want to do the following code:

>> lex = parseLexicon(r'''
 :- S,NP
 He => NP {sem=\x.he(x)} [1.0]
 Walks => S\NP {sem=\X. walk(X)} [1.0]
 There => S\S {sem=\x . there(x)} [1.0]
 ''')
>> parser = CCGChartParser(lex)
>> all_parses = parser.nbest_parse(“He walks 
there”.split(),n=100)
>> for parse in all_parses: 
 printCCGDerivation(parse)

but existing CCG implementation of NLTK does not support {sem=\x.he(x)} [1.0] kinds of semantic parts in lexicon.

Are there Any other CCG implementations that can handle this? Or can i represent this inside of NLTK?

@crackjack no, unfortunaltely. there were a master thesis project implementation on this but it is not completed. i contacted with thesis advisor, he said project is no longer maintaned. — ayyayyekokojambo, Jan 18 '15 at 20:56
I'm that guy. The semantics predicate was recently implemented. The probabilistic parsing for CCG is on the horizon. Please see my answer below. — Tanin, Apr 03 '16 at 17:18

score 3 · Answer 1 · edited May 06 '15 at 01:30

3

Unfortunately no, this does not exist yet. I too have been looking at this space. It seems to be in the works mentioned here on their wiki - Semantic-Parsing

If you are interested in other languages / frameworks, take a peek at Semantic Parsing with Execution, Stanford or The University of Washington Semantic Parsing Framework.

If you want to build something from the ground up, you might want to obtain the CCGBank or revive C&C Tools.

Most of the above is in Java, but I have seen attempts to parse the C&C Marked file in Python.

I personally would like to see CCG come to Node.js.

edited May 06 '15 at 01:30

Nathan Tuggy

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answered May 06 '15 at 01:11

Rob Ellis

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Thanks for you info. I checked the page where I can download CCGBank (the linguistic data consortium site, https://catalog.ldc.upenn.edu/ldc2005t13) but it seems I will be charged to obtain. – Yohan Chung Feb 28 '17 at 00:13

Tanin · Accepted Answer · 2016-04-03T17:18:52.427

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NLTK CCG recently supports semantics predicate (Lambda-Calculus representation) computation. Please see the tests here: https://github.com/nltk/nltk/blob/develop/nltk/test/ccg_semantics.doctest

The probabilistic parsing for CCG is on the horizon: https://github.com/nltk/nltk/issues/1356

edited Apr 03 '16 at 17:18

answered Apr 03 '16 at 05:54

Tanin

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I do appreciate your answer after all that time. thank you. – ayyayyekokojambo Apr 04 '16 at 07:47
If I understand correctly, this is just a parser, but for full functionality we will need wide coverage lexicon? – user1700890 Apr 26 '19 at 20:18

score -1 · Answer 3 · answered Sep 16 '19 at 23:37

-1

If you don't mind switching to Common LISP, there is a ccg tool (CCGlab) developed by Cem Bozsahin. It also has PCCG training. https://github.com/bozsahin/ccglab

answered Sep 16 '19 at 23:37

CSaki

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Lambda-Calculus Representation in NLTK CCG

3 Answers3