553 lines
30 KiB
Plaintext
553 lines
30 KiB
Plaintext
.. Copyright (C) 2001-2023 NLTK Project
|
|
.. For license information, see LICENSE.TXT
|
|
|
|
==============================================
|
|
Combinatory Categorial Grammar with semantics
|
|
==============================================
|
|
|
|
-----
|
|
Chart
|
|
-----
|
|
|
|
|
|
>>> from nltk.ccg import chart, lexicon
|
|
>>> from nltk.ccg.chart import printCCGDerivation
|
|
|
|
No semantics
|
|
-------------------
|
|
|
|
>>> lex = lexicon.fromstring('''
|
|
... :- S, NP, N
|
|
... She => NP
|
|
... has => (S\\NP)/NP
|
|
... books => NP
|
|
... ''',
|
|
... False)
|
|
|
|
>>> parser = chart.CCGChartParser(lex, chart.DefaultRuleSet)
|
|
>>> parses = list(parser.parse("She has books".split()))
|
|
>>> print(str(len(parses)) + " parses")
|
|
3 parses
|
|
|
|
>>> printCCGDerivation(parses[0])
|
|
She has books
|
|
NP ((S\NP)/NP) NP
|
|
-------------------->
|
|
(S\NP)
|
|
-------------------------<
|
|
S
|
|
|
|
>>> printCCGDerivation(parses[1])
|
|
She has books
|
|
NP ((S\NP)/NP) NP
|
|
----->T
|
|
(S/(S\NP))
|
|
-------------------->
|
|
(S\NP)
|
|
------------------------->
|
|
S
|
|
|
|
|
|
>>> printCCGDerivation(parses[2])
|
|
She has books
|
|
NP ((S\NP)/NP) NP
|
|
----->T
|
|
(S/(S\NP))
|
|
------------------>B
|
|
(S/NP)
|
|
------------------------->
|
|
S
|
|
|
|
Simple semantics
|
|
-------------------
|
|
|
|
>>> lex = lexicon.fromstring('''
|
|
... :- S, NP, N
|
|
... She => NP {she}
|
|
... has => (S\\NP)/NP {\\x y.have(y, x)}
|
|
... a => NP/N {\\P.exists z.P(z)}
|
|
... book => N {book}
|
|
... ''',
|
|
... True)
|
|
|
|
>>> parser = chart.CCGChartParser(lex, chart.DefaultRuleSet)
|
|
>>> parses = list(parser.parse("She has a book".split()))
|
|
>>> print(str(len(parses)) + " parses")
|
|
7 parses
|
|
|
|
>>> printCCGDerivation(parses[0])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (NP/N) {\P.exists z.P(z)} N {book}
|
|
------------------------------------->
|
|
NP {exists z.book(z)}
|
|
------------------------------------------------------------------->
|
|
(S\NP) {\y.have(y,exists z.book(z))}
|
|
-----------------------------------------------------------------------------<
|
|
S {have(she,exists z.book(z))}
|
|
|
|
>>> printCCGDerivation(parses[1])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (NP/N) {\P.exists z.P(z)} N {book}
|
|
--------------------------------------------------------->B
|
|
((S\NP)/N) {\P y.have(y,exists z.P(z))}
|
|
------------------------------------------------------------------->
|
|
(S\NP) {\y.have(y,exists z.book(z))}
|
|
-----------------------------------------------------------------------------<
|
|
S {have(she,exists z.book(z))}
|
|
|
|
>>> printCCGDerivation(parses[2])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (NP/N) {\P.exists z.P(z)} N {book}
|
|
---------->T
|
|
(S/(S\NP)) {\F.F(she)}
|
|
------------------------------------->
|
|
NP {exists z.book(z)}
|
|
------------------------------------------------------------------->
|
|
(S\NP) {\y.have(y,exists z.book(z))}
|
|
----------------------------------------------------------------------------->
|
|
S {have(she,exists z.book(z))}
|
|
|
|
>>> printCCGDerivation(parses[3])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (NP/N) {\P.exists z.P(z)} N {book}
|
|
---------->T
|
|
(S/(S\NP)) {\F.F(she)}
|
|
--------------------------------------------------------->B
|
|
((S\NP)/N) {\P y.have(y,exists z.P(z))}
|
|
------------------------------------------------------------------->
|
|
(S\NP) {\y.have(y,exists z.book(z))}
|
|
----------------------------------------------------------------------------->
|
|
S {have(she,exists z.book(z))}
|
|
|
|
>>> printCCGDerivation(parses[4])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (NP/N) {\P.exists z.P(z)} N {book}
|
|
---------->T
|
|
(S/(S\NP)) {\F.F(she)}
|
|
---------------------------------------->B
|
|
(S/NP) {\x.have(she,x)}
|
|
------------------------------------->
|
|
NP {exists z.book(z)}
|
|
----------------------------------------------------------------------------->
|
|
S {have(she,exists z.book(z))}
|
|
|
|
>>> printCCGDerivation(parses[5])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (NP/N) {\P.exists z.P(z)} N {book}
|
|
---------->T
|
|
(S/(S\NP)) {\F.F(she)}
|
|
--------------------------------------------------------->B
|
|
((S\NP)/N) {\P y.have(y,exists z.P(z))}
|
|
------------------------------------------------------------------->B
|
|
(S/N) {\P.have(she,exists z.P(z))}
|
|
----------------------------------------------------------------------------->
|
|
S {have(she,exists z.book(z))}
|
|
|
|
>>> printCCGDerivation(parses[6])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (NP/N) {\P.exists z.P(z)} N {book}
|
|
---------->T
|
|
(S/(S\NP)) {\F.F(she)}
|
|
---------------------------------------->B
|
|
(S/NP) {\x.have(she,x)}
|
|
------------------------------------------------------------------->B
|
|
(S/N) {\P.have(she,exists z.P(z))}
|
|
----------------------------------------------------------------------------->
|
|
S {have(she,exists z.book(z))}
|
|
|
|
Complex semantics
|
|
-------------------
|
|
|
|
>>> lex = lexicon.fromstring('''
|
|
... :- S, NP, N
|
|
... She => NP {she}
|
|
... has => (S\\NP)/NP {\\x y.have(y, x)}
|
|
... a => ((S\\NP)\\((S\\NP)/NP))/N {\\P R x.(exists z.P(z) & R(z,x))}
|
|
... book => N {book}
|
|
... ''',
|
|
... True)
|
|
|
|
>>> parser = chart.CCGChartParser(lex, chart.DefaultRuleSet)
|
|
>>> parses = list(parser.parse("She has a book".split()))
|
|
>>> print(str(len(parses)) + " parses")
|
|
2 parses
|
|
|
|
>>> printCCGDerivation(parses[0])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (((S\NP)\((S\NP)/NP))/N) {\P R x.(exists z.P(z) & R(z,x))} N {book}
|
|
---------------------------------------------------------------------->
|
|
((S\NP)\((S\NP)/NP)) {\R x.(exists z.book(z) & R(z,x))}
|
|
----------------------------------------------------------------------------------------------------<
|
|
(S\NP) {\x.(exists z.book(z) & have(x,z))}
|
|
--------------------------------------------------------------------------------------------------------------<
|
|
S {(exists z.book(z) & have(she,z))}
|
|
|
|
>>> printCCGDerivation(parses[1])
|
|
She has a book
|
|
NP {she} ((S\NP)/NP) {\x y.have(y,x)} (((S\NP)\((S\NP)/NP))/N) {\P R x.(exists z.P(z) & R(z,x))} N {book}
|
|
---------->T
|
|
(S/(S\NP)) {\F.F(she)}
|
|
---------------------------------------------------------------------->
|
|
((S\NP)\((S\NP)/NP)) {\R x.(exists z.book(z) & R(z,x))}
|
|
----------------------------------------------------------------------------------------------------<
|
|
(S\NP) {\x.(exists z.book(z) & have(x,z))}
|
|
-------------------------------------------------------------------------------------------------------------->
|
|
S {(exists z.book(z) & have(she,z))}
|
|
|
|
Using conjunctions
|
|
---------------------
|
|
|
|
# TODO: The semantics of "and" should have been more flexible
|
|
>>> lex = lexicon.fromstring('''
|
|
... :- S, NP, N
|
|
... I => NP {I}
|
|
... cook => (S\\NP)/NP {\\x y.cook(x,y)}
|
|
... and => var\\.,var/.,var {\\P Q x y.(P(x,y) & Q(x,y))}
|
|
... eat => (S\\NP)/NP {\\x y.eat(x,y)}
|
|
... the => NP/N {\\x.the(x)}
|
|
... bacon => N {bacon}
|
|
... ''',
|
|
... True)
|
|
|
|
>>> parser = chart.CCGChartParser(lex, chart.DefaultRuleSet)
|
|
>>> parses = list(parser.parse("I cook and eat the bacon".split()))
|
|
>>> print(str(len(parses)) + " parses")
|
|
7 parses
|
|
|
|
>>> printCCGDerivation(parses[0])
|
|
I cook and eat the bacon
|
|
NP {I} ((S\NP)/NP) {\x y.cook(x,y)} ((_var0\.,_var0)/.,_var0) {\P Q x y.(P(x,y) & Q(x,y))} ((S\NP)/NP) {\x y.eat(x,y)} (NP/N) {\x.the(x)} N {bacon}
|
|
------------------------------------------------------------------------------------->
|
|
(((S\NP)/NP)\.,((S\NP)/NP)) {\Q x y.(eat(x,y) & Q(x,y))}
|
|
-------------------------------------------------------------------------------------------------------------------<
|
|
((S\NP)/NP) {\x y.(eat(x,y) & cook(x,y))}
|
|
------------------------------->
|
|
NP {the(bacon)}
|
|
-------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
(S\NP) {\y.(eat(the(bacon),y) & cook(the(bacon),y))}
|
|
----------------------------------------------------------------------------------------------------------------------------------------------------------<
|
|
S {(eat(the(bacon),I) & cook(the(bacon),I))}
|
|
|
|
>>> printCCGDerivation(parses[1])
|
|
I cook and eat the bacon
|
|
NP {I} ((S\NP)/NP) {\x y.cook(x,y)} ((_var0\.,_var0)/.,_var0) {\P Q x y.(P(x,y) & Q(x,y))} ((S\NP)/NP) {\x y.eat(x,y)} (NP/N) {\x.the(x)} N {bacon}
|
|
------------------------------------------------------------------------------------->
|
|
(((S\NP)/NP)\.,((S\NP)/NP)) {\Q x y.(eat(x,y) & Q(x,y))}
|
|
-------------------------------------------------------------------------------------------------------------------<
|
|
((S\NP)/NP) {\x y.(eat(x,y) & cook(x,y))}
|
|
--------------------------------------------------------------------------------------------------------------------------------------->B
|
|
((S\NP)/N) {\x y.(eat(the(x),y) & cook(the(x),y))}
|
|
-------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
(S\NP) {\y.(eat(the(bacon),y) & cook(the(bacon),y))}
|
|
----------------------------------------------------------------------------------------------------------------------------------------------------------<
|
|
S {(eat(the(bacon),I) & cook(the(bacon),I))}
|
|
|
|
>>> printCCGDerivation(parses[2])
|
|
I cook and eat the bacon
|
|
NP {I} ((S\NP)/NP) {\x y.cook(x,y)} ((_var0\.,_var0)/.,_var0) {\P Q x y.(P(x,y) & Q(x,y))} ((S\NP)/NP) {\x y.eat(x,y)} (NP/N) {\x.the(x)} N {bacon}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
------------------------------------------------------------------------------------->
|
|
(((S\NP)/NP)\.,((S\NP)/NP)) {\Q x y.(eat(x,y) & Q(x,y))}
|
|
-------------------------------------------------------------------------------------------------------------------<
|
|
((S\NP)/NP) {\x y.(eat(x,y) & cook(x,y))}
|
|
------------------------------->
|
|
NP {the(bacon)}
|
|
-------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
(S\NP) {\y.(eat(the(bacon),y) & cook(the(bacon),y))}
|
|
---------------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
S {(eat(the(bacon),I) & cook(the(bacon),I))}
|
|
|
|
>>> printCCGDerivation(parses[3])
|
|
I cook and eat the bacon
|
|
NP {I} ((S\NP)/NP) {\x y.cook(x,y)} ((_var0\.,_var0)/.,_var0) {\P Q x y.(P(x,y) & Q(x,y))} ((S\NP)/NP) {\x y.eat(x,y)} (NP/N) {\x.the(x)} N {bacon}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
------------------------------------------------------------------------------------->
|
|
(((S\NP)/NP)\.,((S\NP)/NP)) {\Q x y.(eat(x,y) & Q(x,y))}
|
|
-------------------------------------------------------------------------------------------------------------------<
|
|
((S\NP)/NP) {\x y.(eat(x,y) & cook(x,y))}
|
|
--------------------------------------------------------------------------------------------------------------------------------------->B
|
|
((S\NP)/N) {\x y.(eat(the(x),y) & cook(the(x),y))}
|
|
-------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
(S\NP) {\y.(eat(the(bacon),y) & cook(the(bacon),y))}
|
|
---------------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
S {(eat(the(bacon),I) & cook(the(bacon),I))}
|
|
|
|
>>> printCCGDerivation(parses[4])
|
|
I cook and eat the bacon
|
|
NP {I} ((S\NP)/NP) {\x y.cook(x,y)} ((_var0\.,_var0)/.,_var0) {\P Q x y.(P(x,y) & Q(x,y))} ((S\NP)/NP) {\x y.eat(x,y)} (NP/N) {\x.the(x)} N {bacon}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
------------------------------------------------------------------------------------->
|
|
(((S\NP)/NP)\.,((S\NP)/NP)) {\Q x y.(eat(x,y) & Q(x,y))}
|
|
-------------------------------------------------------------------------------------------------------------------<
|
|
((S\NP)/NP) {\x y.(eat(x,y) & cook(x,y))}
|
|
--------------------------------------------------------------------------------------------------------------------------->B
|
|
(S/NP) {\x.(eat(x,I) & cook(x,I))}
|
|
------------------------------->
|
|
NP {the(bacon)}
|
|
---------------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
S {(eat(the(bacon),I) & cook(the(bacon),I))}
|
|
|
|
>>> printCCGDerivation(parses[5])
|
|
I cook and eat the bacon
|
|
NP {I} ((S\NP)/NP) {\x y.cook(x,y)} ((_var0\.,_var0)/.,_var0) {\P Q x y.(P(x,y) & Q(x,y))} ((S\NP)/NP) {\x y.eat(x,y)} (NP/N) {\x.the(x)} N {bacon}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
------------------------------------------------------------------------------------->
|
|
(((S\NP)/NP)\.,((S\NP)/NP)) {\Q x y.(eat(x,y) & Q(x,y))}
|
|
-------------------------------------------------------------------------------------------------------------------<
|
|
((S\NP)/NP) {\x y.(eat(x,y) & cook(x,y))}
|
|
--------------------------------------------------------------------------------------------------------------------------------------->B
|
|
((S\NP)/N) {\x y.(eat(the(x),y) & cook(the(x),y))}
|
|
----------------------------------------------------------------------------------------------------------------------------------------------->B
|
|
(S/N) {\x.(eat(the(x),I) & cook(the(x),I))}
|
|
---------------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
S {(eat(the(bacon),I) & cook(the(bacon),I))}
|
|
|
|
>>> printCCGDerivation(parses[6])
|
|
I cook and eat the bacon
|
|
NP {I} ((S\NP)/NP) {\x y.cook(x,y)} ((_var0\.,_var0)/.,_var0) {\P Q x y.(P(x,y) & Q(x,y))} ((S\NP)/NP) {\x y.eat(x,y)} (NP/N) {\x.the(x)} N {bacon}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
------------------------------------------------------------------------------------->
|
|
(((S\NP)/NP)\.,((S\NP)/NP)) {\Q x y.(eat(x,y) & Q(x,y))}
|
|
-------------------------------------------------------------------------------------------------------------------<
|
|
((S\NP)/NP) {\x y.(eat(x,y) & cook(x,y))}
|
|
--------------------------------------------------------------------------------------------------------------------------->B
|
|
(S/NP) {\x.(eat(x,I) & cook(x,I))}
|
|
----------------------------------------------------------------------------------------------------------------------------------------------->B
|
|
(S/N) {\x.(eat(the(x),I) & cook(the(x),I))}
|
|
---------------------------------------------------------------------------------------------------------------------------------------------------------->
|
|
S {(eat(the(bacon),I) & cook(the(bacon),I))}
|
|
|
|
Tests from published papers
|
|
------------------------------
|
|
|
|
An example from "CCGbank: A Corpus of CCG Derivations and Dependency Structures Extracted from the Penn Treebank", Hockenmaier and Steedman, 2007, Page 359, https://www.aclweb.org/anthology/J/J07/J07-3004.pdf
|
|
|
|
>>> lex = lexicon.fromstring('''
|
|
... :- S, NP
|
|
... I => NP {I}
|
|
... give => ((S\\NP)/NP)/NP {\\x y z.give(y,x,z)}
|
|
... them => NP {them}
|
|
... money => NP {money}
|
|
... ''',
|
|
... True)
|
|
|
|
>>> parser = chart.CCGChartParser(lex, chart.DefaultRuleSet)
|
|
>>> parses = list(parser.parse("I give them money".split()))
|
|
>>> print(str(len(parses)) + " parses")
|
|
3 parses
|
|
|
|
>>> printCCGDerivation(parses[0])
|
|
I give them money
|
|
NP {I} (((S\NP)/NP)/NP) {\x y z.give(y,x,z)} NP {them} NP {money}
|
|
-------------------------------------------------->
|
|
((S\NP)/NP) {\y z.give(y,them,z)}
|
|
-------------------------------------------------------------->
|
|
(S\NP) {\z.give(money,them,z)}
|
|
----------------------------------------------------------------------<
|
|
S {give(money,them,I)}
|
|
|
|
>>> printCCGDerivation(parses[1])
|
|
I give them money
|
|
NP {I} (((S\NP)/NP)/NP) {\x y z.give(y,x,z)} NP {them} NP {money}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
-------------------------------------------------->
|
|
((S\NP)/NP) {\y z.give(y,them,z)}
|
|
-------------------------------------------------------------->
|
|
(S\NP) {\z.give(money,them,z)}
|
|
---------------------------------------------------------------------->
|
|
S {give(money,them,I)}
|
|
|
|
|
|
>>> printCCGDerivation(parses[2])
|
|
I give them money
|
|
NP {I} (((S\NP)/NP)/NP) {\x y z.give(y,x,z)} NP {them} NP {money}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
-------------------------------------------------->
|
|
((S\NP)/NP) {\y z.give(y,them,z)}
|
|
---------------------------------------------------------->B
|
|
(S/NP) {\y.give(y,them,I)}
|
|
---------------------------------------------------------------------->
|
|
S {give(money,them,I)}
|
|
|
|
|
|
An example from "CCGbank: A Corpus of CCG Derivations and Dependency Structures Extracted from the Penn Treebank", Hockenmaier and Steedman, 2007, Page 359, https://www.aclweb.org/anthology/J/J07/J07-3004.pdf
|
|
|
|
>>> lex = lexicon.fromstring('''
|
|
... :- N, NP, S
|
|
... money => N {money}
|
|
... that => (N\\N)/(S/NP) {\\P Q x.(P(x) & Q(x))}
|
|
... I => NP {I}
|
|
... give => ((S\\NP)/NP)/NP {\\x y z.give(y,x,z)}
|
|
... them => NP {them}
|
|
... ''',
|
|
... True)
|
|
|
|
>>> parser = chart.CCGChartParser(lex, chart.DefaultRuleSet)
|
|
>>> parses = list(parser.parse("money that I give them".split()))
|
|
>>> print(str(len(parses)) + " parses")
|
|
3 parses
|
|
|
|
>>> printCCGDerivation(parses[0])
|
|
money that I give them
|
|
N {money} ((N\N)/(S/NP)) {\P Q x.(P(x) & Q(x))} NP {I} (((S\NP)/NP)/NP) {\x y z.give(y,x,z)} NP {them}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
-------------------------------------------------->
|
|
((S\NP)/NP) {\y z.give(y,them,z)}
|
|
---------------------------------------------------------->B
|
|
(S/NP) {\y.give(y,them,I)}
|
|
------------------------------------------------------------------------------------------------->
|
|
(N\N) {\Q x.(give(x,them,I) & Q(x))}
|
|
------------------------------------------------------------------------------------------------------------<
|
|
N {\x.(give(x,them,I) & money(x))}
|
|
|
|
>>> printCCGDerivation(parses[1])
|
|
money that I give them
|
|
N {money} ((N\N)/(S/NP)) {\P Q x.(P(x) & Q(x))} NP {I} (((S\NP)/NP)/NP) {\x y z.give(y,x,z)} NP {them}
|
|
----------->T
|
|
(N/(N\N)) {\F.F(money)}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
-------------------------------------------------->
|
|
((S\NP)/NP) {\y z.give(y,them,z)}
|
|
---------------------------------------------------------->B
|
|
(S/NP) {\y.give(y,them,I)}
|
|
------------------------------------------------------------------------------------------------->
|
|
(N\N) {\Q x.(give(x,them,I) & Q(x))}
|
|
------------------------------------------------------------------------------------------------------------>
|
|
N {\x.(give(x,them,I) & money(x))}
|
|
|
|
>>> printCCGDerivation(parses[2])
|
|
money that I give them
|
|
N {money} ((N\N)/(S/NP)) {\P Q x.(P(x) & Q(x))} NP {I} (((S\NP)/NP)/NP) {\x y z.give(y,x,z)} NP {them}
|
|
----------->T
|
|
(N/(N\N)) {\F.F(money)}
|
|
-------------------------------------------------->B
|
|
(N/(S/NP)) {\P x.(P(x) & money(x))}
|
|
-------->T
|
|
(S/(S\NP)) {\F.F(I)}
|
|
-------------------------------------------------->
|
|
((S\NP)/NP) {\y z.give(y,them,z)}
|
|
---------------------------------------------------------->B
|
|
(S/NP) {\y.give(y,them,I)}
|
|
------------------------------------------------------------------------------------------------------------>
|
|
N {\x.(give(x,them,I) & money(x))}
|
|
|
|
|
|
-------
|
|
Lexicon
|
|
-------
|
|
|
|
>>> from nltk.ccg import lexicon
|
|
|
|
Parse lexicon with semantics
|
|
|
|
>>> print(str(lexicon.fromstring(
|
|
... '''
|
|
... :- S,NP
|
|
...
|
|
... IntransVsg :: S\\NP[sg]
|
|
...
|
|
... sleeps => IntransVsg {\\x.sleep(x)}
|
|
... eats => S\\NP[sg]/NP {\\x y.eat(x,y)}
|
|
...
|
|
... and => var\\var/var {\\x y.x & y}
|
|
... ''',
|
|
... True
|
|
... )))
|
|
and => ((_var0\_var0)/_var0) {(\x y.x & y)}
|
|
eats => ((S\NP['sg'])/NP) {\x y.eat(x,y)}
|
|
sleeps => (S\NP['sg']) {\x.sleep(x)}
|
|
|
|
Parse lexicon without semantics
|
|
|
|
>>> print(str(lexicon.fromstring(
|
|
... '''
|
|
... :- S,NP
|
|
...
|
|
... IntransVsg :: S\\NP[sg]
|
|
...
|
|
... sleeps => IntransVsg
|
|
... eats => S\\NP[sg]/NP {sem=\\x y.eat(x,y)}
|
|
...
|
|
... and => var\\var/var
|
|
... ''',
|
|
... False
|
|
... )))
|
|
and => ((_var0\_var0)/_var0)
|
|
eats => ((S\NP['sg'])/NP)
|
|
sleeps => (S\NP['sg'])
|
|
|
|
Semantics are missing
|
|
|
|
>>> print(str(lexicon.fromstring(
|
|
... '''
|
|
... :- S,NP
|
|
...
|
|
... eats => S\\NP[sg]/NP
|
|
... ''',
|
|
... True
|
|
... )))
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: eats => S\NP[sg]/NP must contain semantics because include_semantics is set to True
|
|
|
|
|
|
------------------------------------
|
|
CCG combinator semantics computation
|
|
------------------------------------
|
|
|
|
>>> from nltk.sem.logic import *
|
|
>>> from nltk.ccg.logic import *
|
|
|
|
>>> read_expr = Expression.fromstring
|
|
|
|
Compute semantics from function application
|
|
|
|
>>> print(str(compute_function_semantics(read_expr(r'\x.P(x)'), read_expr(r'book'))))
|
|
P(book)
|
|
|
|
>>> print(str(compute_function_semantics(read_expr(r'\P.P(book)'), read_expr(r'read'))))
|
|
read(book)
|
|
|
|
>>> print(str(compute_function_semantics(read_expr(r'\P.P(book)'), read_expr(r'\x.read(x)'))))
|
|
read(book)
|
|
|
|
Compute semantics from composition
|
|
|
|
>>> print(str(compute_composition_semantics(read_expr(r'\x.P(x)'), read_expr(r'\x.Q(x)'))))
|
|
\x.P(Q(x))
|
|
|
|
>>> print(str(compute_composition_semantics(read_expr(r'\x.P(x)'), read_expr(r'read'))))
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: `read` must be a lambda expression
|
|
|
|
Compute semantics from substitution
|
|
|
|
>>> print(str(compute_substitution_semantics(read_expr(r'\x y.P(x,y)'), read_expr(r'\x.Q(x)'))))
|
|
\x.P(x,Q(x))
|
|
|
|
>>> print(str(compute_substitution_semantics(read_expr(r'\x.P(x)'), read_expr(r'read'))))
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: `\x.P(x)` must be a lambda expression with 2 arguments
|
|
|
|
Compute type-raise semantics
|
|
|
|
>>> print(str(compute_type_raised_semantics(read_expr(r'\x.P(x)'))))
|
|
\F x.F(P(x))
|
|
|
|
>>> print(str(compute_type_raised_semantics(read_expr(r'\x.F(x)'))))
|
|
\F1 x.F1(F(x))
|
|
|
|
>>> print(str(compute_type_raised_semantics(read_expr(r'\x y z.P(x,y,z)'))))
|
|
\F x y z.F(P(x,y,z))
|