Writing My Prolog Code - prolog

I am writing my first Prolog code, and I am have some difficulties with it I was wondering if anyone could help me out.
I am writing a program that needs to follow the following rules:
for Verb phrases., noun phrases come before transitive verbs.
subjects (nominative noun phrases) are followed by ga
Direct Objects (nominative noun phrases are followed by o.
it must be able to form these sentences with the given words in the code:
Adamu ga waraimasu (adam laughs)
Iive ga nakimasu (eve cries)
Adamu ga Iivu O mimasi (adam watches Eve)
Iivu ga Adamu O tetsudaimasu (eve helps adam)
here is my code. It it mostly complete except, I don't know if the rules are correct in the code:
Japanese([adamu ],[nounphrase],[adam],[entity]).
Japanese([iivu ],[nounphrase],[eve],[entity]).
Japanese([waraimasu ],[verb,intransitive],[laughs],[property]).
Japanese([nakimasu],[verb,intransitive],[cries],[property]).
Japanese([mimasu ],[verb,transitive],[watches],[relation]).
Japanese([tetsudaimasu ],[verb,transitive],[helps],[relation]).
Japanese(A,[verbphrase],B,[property]):-
Japanese(A,[verb,intransitive],B,[property]).
Japanese(A,[nounphrase,accusative],B,[entity]):-
Japanese(C,[nounphrase],B,[entity]),
append([ga],C,A).
Japanese(A,[verbphrase],B,[property]):-
Japanese(C,[verb,transitive],D,[relation]),
Japanese(E,[nounphrase,accusative],F,[entity]),
append(C,E,A),
append(D,F,B).
Japanese(A,[sentence],B,[proposition]):-
Japanese(C,[nounphrase],D,[entity]),
Japanese(E,[verbphrase],F,[property]),
append(E,C,A),
append(F,D,B).

Related

Gensim most_similar() with Fasttext word vectors return useless/meaningless words

I'm using Gensim with Fasttext Word vectors for return similar words.
This is my code:
import gensim
model = gensim.models.KeyedVectors.load_word2vec_format('cc.it.300.vec')
words = model.most_similar(positive=['sole'],topn=10)
print(words)
This will return:
[('sole.', 0.6860659122467041), ('sole.Ma', 0.6750558614730835), ('sole.Il', 0.6727924942970276), ('sole.E', 0.6680260896682739), ('sole.A', 0.6419174075126648), ('sole.È', 0.6401025652885437), ('splende', 0.6336565613746643), ('sole.La', 0.6049465537071228), ('sole.I', 0.5922051668167114), ('sole.Un', 0.5904430150985718)]
The problem is that "sole" ("sun", in english) return a series of words with a dot in it (like sole., sole.Ma, ecc...). Where is the problem? Why most_similar return this meaningless word?
EDIT
I tried with english word vector and the word "sun" return this:
[('sunlight', 0.6970556974411011), ('sunshine', 0.6911839246749878), ('sun.', 0.6835992336273193), ('sun-', 0.6780728101730347), ('suns', 0.6730450391769409), ('moon', 0.6499731540679932), ('solar', 0.6437565088272095), ('rays', 0.6423950791358948), ('shade', 0.6366724371910095), ('sunrays', 0.6306195259094238)] 
Is it impossible to reproduce results like relatedwords.org?
Perhaps the bigger question is: why does the Facebook FastText cc.it.300.vec model include so many meaningless words? (I haven't noticed that before – is there any chance you've downloaded a peculiar model that has decorated words with extra analytical markup?)
To gain the unique benefits of FastText – including the ability to synthesize plausible (better-than-nothing) vectors for out-of-vocabulary words – you may not want to use the general load_word2vec_format() on the plain-text .vec file, but rather a Facebook-FastText specific load method on the .bin file. See:
https://radimrehurek.com/gensim/models/fasttext.html#gensim.models.fasttext.load_facebook_vectors
(I'm not sure that will help with these results, but if choosing to use FastText, you may be interesting it using it "fully".)
Finally, given the source of this training – common-crawl text from the open web, which may contain lots of typos/junk – these might be legimate word-like tokens, essentially typos of sole, that appear often enough in the training data to get word-vectors. (And because they really are typo-synonyms for 'sole', they're not necessarily bad results for all purposes, just for your desired purpose of only seeing "real-ish" words.)
You might find it helpful to try using the restrict_vocab argument of most_similar(), to only receive results from the leading (most-frequent) part of all known word-vectors. For example, to only get results from among the top 50000 words:
words = model.most_similar(positive=['sole'], topn=10, restrict_vocab=50000)
Picking the right value for restrict_vocab might help in practice to leave out long-tail 'junk' words, while still providing the real/common similar words you seek.

How to set up training and feature template files for NER? - CRF++

For the problem of named entity recognition,
After tokenizing the sentences, how do you set up the columns? it looks like one column in the documentation is POS tag, but where do these come from? Am I supposed to tag the POS myself or is there a tool to generate these?
What is the next column represent? A class like PERSON, LOCATION, etc? and does it have to be in any particular format?
Is there any example of a completed training file and template for NER?
You can find example training and test data in the crf++ repo here. The training data for noun phrase chunking looks like this:
Confidence NN B
in IN O
the DT B
pound NN I
is VBZ O
widely RB O
expected VBN O
... etc ...
The columns are arbitrary in that they can be anything. CRF++ requires that every line have the same number of columns (or be blank, to separate sentences), not all CRF packages require that. You will have to provide the data values yourself; they are the data the classifier learns from.
While anything can go in the various columns, one convention you should know is IOB Format. To deal with potentially multi-token entities, you mark them as Inside/Outside/Beginning. It may be useful to give an example. Pretend we are training a classifier to detect names - for compactness I'll write this on one line:
John/B Smith/I ate/O an/O apple/O ./O
In columnar format it would look like this:
John B
Smith I
ate O
an O
apple O
. O
With these tags, B (beginning) means the word is the first in an entity, I means a word is inside an entity (it comes after a B tag), and O means the word is not an entity. If you have more than one type of entity it's typical to use labels like B-PERSON or I-PLACE.
The reason for using IOB tags is so that the classifier can learn different transition probabilities for starting, continuing, and ending entities. So if you're learning company names It'll learn that Inc./I-COMPANY usually transitions to an O label because Inc. is usually the last part of a company name.
Templates are another problem and CRF++ uses its own special format, but again, there are examples in the source distribution you can look at. Also see this question.
To answer the comment on my answer, you can generate POS tags using any POS tagger. You don't even have to provide POS tags at all, though they're usually helpful. The other labels can be added by hand or automatically; for example, you can use a list of known nouns as a starting point. Here's an example using spaCy for a simple name detector:
import spacy
nlp = spacy.load('en')
names = ['John', 'Jane', etc...]
text = nlp("John ate an apple.")
for word in text:
person = 'O' # default not a person
if str(word) in names:
person = 'B-PERSON'
print(str(word), word.pos_, person)

Extracting food items from sentences

Given a sentence:
I had peanut butter and jelly sandwich and a cup of coffee for
breakfast
I want to be able to extract the following food items from it:
peanut butter and jelly sandwich
coffee
Till now, using POS tagging, I have been able to extract the individual food items, i.e.
peanut, butter, jelly, sandwich, coffee
But like I said, what I need is peanut butter and jelly sandwich instead of the individual items.
Is there some way of doing this without having a corpus or database of food items in the backend?
You can attempt it without using a trained set which contains a corpus of food items, but the approach shall work without it too.
Instead of doing simple POS tagging, do a dependency parsing combined with POS tagging.
That way would be able to find relations between multiple tokens of the phrase, and parsing the dependency tree with restricted conditions like noun-noun dependencies you shall be able to find relevant chunk.
You can use spacy for dep parsing. Here is output from displacy :
https://demos.explosion.ai/displacy/?text=peanut%20butter%20and%20jelly%20sandwich%20is%20delicious&model=en&cpu=1&cph=1
You can use freely available data here, or something better:
https://en.wikipedia.org/wiki/Lists_of_foods as a training set to
create a base set of food items (the hyperlinks in the crawled tree)
Based on the dependency parsing on your new data, you can keep
enriching the base data. For example: if 'butter' exists in your
corpus, and 'peanut butter' is a frequently encountered pair of
tokens, then 'peanut' and 'peanut butter' also get added to the
corpus.
The corpus can be maintained in a file which can be loaded in memory
while processing, or database like redis,aerospike etc.
Make sure you work with normalized i.e. small cased, special
characters cleaned, words lemmatized/stemmed, both in corpus and the
processing data. That would increase your coverage and accuracy.
First extract all Noun phrases using NLTK's Chunking (code copied from here):
import nltk
import re
import pprint
from nltk import Tree
import pdb
patterns="""
NP: {<JJ>*<NN*>+}
{<JJ>*<NN*><CC>*<NN*>+}
{<NP><CC><NP>}
{<RB><JJ>*<NN*>+}
"""
NPChunker = nltk.RegexpParser(patterns)
def prepare_text(input):
sentences = nltk.sent_tokenize(input)
sentences = [nltk.word_tokenize(sent) for sent in sentences]
sentences = [nltk.pos_tag(sent) for sent in sentences]
sentences = [NPChunker.parse(sent) for sent in sentences]
return sentences
def parsed_text_to_NP(sentences):
nps = []
for sent in sentences:
tree = NPChunker.parse(sent)
print(tree)
for subtree in tree.subtrees():
if subtree.label() == 'NP':
t = subtree
t = ' '.join(word for word, tag in t.leaves())
nps.append(t)
return nps
def sent_parse(input):
sentences = prepare_text(input)
nps = parsed_text_to_NP(sentences)
return nps
if __name__ == '__main__':
print(sent_parse('I ate peanut butter and beef burger and a cup of coffee for breakfast.'))
This will POS tag your sentences and uses a regex parser to extract Noun Phrases.
1.Define and Refine your noun phrase regex
You'll need to change the patterns regex to define and refine your Noun phrases.
For example is telling the parser than an NP followed by a coordinator (CC) like ''and'' and another NP is itself an NP.
2.Change from NLTK POS tagger to Stanford POS tagger
Also I noted that NLTK's POS tagger is not performing very well (e.g. It considers had peanut as a verb phrase. You can change the POS tagger to Stanford Parser if you want.
3.Remove smaller noun phrases:
After you have extracted all the Noun phrases for a sentence, you can remove the ones that are part of a bigger noun phrase. For example in the following example beef burger and peanut butter should be removed because
they're a part of a bigger noun phrase peanut butter and beef burger.
4.Remove noun phrases which none of the words are in a food lexicon
you will get noun phrases like school bus. if none of school and bus is in a food lexicon that you can compile from Wikipedia or WordNet then you remove the noun phrase. In this case remove cup and breakfast because they're not hopefully in your food lexicon.
The current code returns
['peanut butter and beef burger', 'peanut butter', 'beef burger', 'cup', 'coffee', 'breakfast']
for input
print(sent_parse('I ate peanut butter and beef burger and a cup of coffee for breakfast.'))
Too much for a comment, but not really an answer:
I think you would at least get closer if when you got two foods without a proper separator and combined them into one food. That would give peanut butter, jelly sandwich, coffee.
If you have correct English you could detect this case by count/non-count. Correcting the original to "I had a peanut butter and jelly sandwich and a cup of coffee for breakfast". Butter is non-count, you can't have "a butter", but you can have "a sandwich". Thus the a must apply to sandwich and despite the and "peanut butter" and "jelly sandwich" must be the same item--"peanut butter and jelly sandwich". Your mistaken sentence would parse the other way, though!
I would be very surprised if you could come up with general rules that cover every case, though. I would come at this sort of thing figuring that a few would leak and need a database to catch.
You could search for n-grams in your text where you vary the value of n. For example, if n=5 then you would extract "peanut butter and jelly sandwich" and "cup of coffee for breakfast", depending on where you start your search in the text for groups of five words. You won't need a corpus of text or a database to make the algorithm work.
A rule based approach with a lexicon of all food items would work here.
You can use GATE for the same and use JAPE rules with it.
In the above example your jape rule would have a condition to find all (np cc np) && np in "FOOD LEIXCON"
Can share a detailed jape code in an event you plan to go this route.

Rewriting sentences while retaining semantic meaning

Is it possible to use WordNet to rewrite a sentence so that the semantic meaning of the sentence still ways the same (or mostly the same)?
Let's say I have this sentence:
Obama met with Putin last week.
Is it possible to use WordNet to rephrase the sentence into alternatives like:
Obama and Putin met the previous week.
Obama and Putin met each other a week ago.
If changing the sentence structure is not possible, can WordNet be used to replace only the relevant synonyms?
For example:
Obama met Putin the previous week.
If the question is the possibility to use WordNet to do sentence paraphrases. It is possible with much grammatical/syntax components. You would need system that:
First get the individual semantics of the tokens and parse the sentence for its syntax.
Then understand the overall semantics of the composite sentence (especially if it's metaphorical)
Then rehash the sentence with some grammatical generator.
Up till now I only know of ACE parser/generator that can do something like that but it takes a LOT of hacking the system to make it work as a paraphrase generator. http://sweaglesw.org/linguistics/ace/
So to answer your questions,
Is it possible to use WordNet to rephrase the sentence into alternatives? Sadly, WordNet isn't a silverbullet. You will need more than semantics for a paraphrase task.
If changing the sentence structure is not possible, can WordNet be used to replace only the relevant synonyms? Yes this is possible. BUT to figure out which synonym is replace-able is hard... And you would also need some morphology/syntax component.
First you will run into a problem of multiple senses per word:
from nltk.corpus import wordnet as wn
sent = "Obama met Putin the previous week"
for i in sent.split():
possible_senses = wn.synsets(i)
print i, len(possible_senses), possible_senses
[out]:
Obama 0 []
met 13 [Synset('meet.v.01'), Synset('meet.v.02'), Synset('converge.v.01'), Synset('meet.v.04'), Synset('meet.v.05'), Synset('meet.v.06'), Synset('meet.v.07'), Synset('meet.v.08'), Synset('meet.v.09'), Synset('meet.v.10'), Synset('meet.v.11'), Synset('suffer.v.10'), Synset('touch.v.05')]
Putin 1 [Synset('putin.n.01')]
the 0 []
previous 3 [Synset('previous.s.01'), Synset('former.s.03'), Synset('previous.s.03')]
week 3 [Synset('week.n.01'), Synset('workweek.n.01'), Synset('week.n.03')]
Then even if you know the sense (let's say the first sense), you get multiple words per sense and not every word can be replaced in the sentence. Moreover, they are in the lemma form not a surface form (e.g. verbs are in their base form (simple present tense) and nouns are in singular):
from nltk.corpus import wordnet as wn
sent = "Obama met Putin the previous week"
for i in sent.split():
possible_senses = wn.synsets(i)
if possible_senses:
print i, possible_senses[0].lemma_names
else:
print i
[out]:
Obama
met ['meet', 'run_into', 'encounter', 'run_across', 'come_across', 'see']
Putin ['Putin', 'Vladimir_Putin', 'Vladimir_Vladimirovich_Putin']
the
previous ['previous', 'old']
week ['week', 'hebdomad']
One approach is grammatical analysis with nltk read more here and after analysis convert your sentence in to active voice or passive voice.

How do I define a SemgrexPattern in Stanford API, to match nodes' text without using {lemma:...}?

I am working with the edu.stanford.nlp.semgrex and edu.stanford.nlp.tress.semgraph packages and am looking for a way to match nodes with a text value other than the lemma: directive.
I couldn't find all possible attribute names in javadoc for SemgrexPattern, only those for lemma, tag, and relational operators - is there a comprehensive list available?
For example, in the following sentence
My take-home pay is $20.
extracting the 'take-home' node is not possible using
(SemgrexPattern.compile( "{lemma:take-home}"))
.matcher( "My take-home pay is $20.").find()
yields false, because take-home is deemed not to be a lemma.
What do I need to do to match nodes with non-lemma, arbitrary text?
Thanks for any advice or comment.
Sorry - I realize that {word:take-home} would work in the example above.
Thanks..

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