[developers] Trigger rules still being requested
Emily M. Bender
ebender at uw.edu
Wed May 3 19:43:04 CEST 2017
Dear all,
I've just run across this issue again, and searched email archive so I could
find the patch to send to the students --- but I wanted to see if fixing
this was
still on the radar.
Thanks,
Emily
On Wed, Feb 17, 2016 at 4:53 PM, Emily M. Bender <ebender at uw.edu> wrote:
> Yeah, unfortunately at least one case does lead to semantically empty
> things combining fairly freely with just about anything: the argument
> composition
> auxiliaries.
>
> Agreed that trigger rules aren't fun, but they can be useful, even in
> smalish
> grammars.
>
> I've sent Dan's patch along to the students, so we're at least not seeing
> spurious
> warnings now.
>
> Emily
>
> On Mon, Feb 15, 2016 at 11:20 AM, Ann Copestake <aac10 at cl.cam.ac.uk>
> wrote:
>
>> It's an expanded version of the mrscomp grammar which I've just checked
>> in to the LKB svn repo. I created it to mirror the dmrscomp grammar and
>> just thought I'd check that it's still possible to avoid trigger rules
>> since I wasn't sure whether the code still allowed it.
>>
>> In terms of whether or not you need trigger rules for a particular
>> grammar, I would suggest just trying it. The additional edges will only
>> explode the search space if the lexical items with null semantics can
>> combine relatively freely with some of the semantically licensed edges. Of
>> course this can happen even if you have trigger rules, if they can't be
>> defined tightly. But I think of trigger rules as a particular form of
>> nastiness that I would be happy not to inflict on grammar writers unless
>> it's essential.
>>
>> oe has offered to fix the warning messages
>>
>> Ann
>>
>>
>> On 15/02/16 19:03, Emily M. Bender wrote:
>>
>> Hi Ann,
>>
>> What kind of small grammar though? There are a few things (argument
>> composition
>> auxiliaries, free word order) that can drastically expand the search
>> space for the generator.
>> I haven't tested this, but I wouldn't be surprised if even right out of
>> the customization
>> system box I could come up with a place where trigger rules are needed.
>> But at any
>> rate, I'd be happy if the warnings that did show up were legitimate ones
>> (and will
>> try applying Dan's patch).
>>
>> Emily
>>
>> On Mon, Feb 15, 2016 at 12:57 PM, Ann Copestake <aac10 at cl.cam.ac.uk>
>> wrote:
>>
>>> I just want to confirm that with a small grammar with a small number of
>>> null semantics entries (five of them), trigger rules are not required to
>>> generate with the LKB. So I think that no warnings about the `missing'
>>> trigger rules should be produced by default with small grammars, though I
>>> don't know what the criteria for switching on the warnings should be.
>>>
>>> Ann
>>>
>>>
>>> On 11/02/16 00:05, Ann Copestake wrote:
>>>
>>> The comment about construction from corpora was really about big
>>> grammars - i looked at the ERG trigger rules about a year ago, and was a
>>> bit horrified ...
>>>
>>> For small grammars, is it really hopelessly inefficient to just run in
>>> the mode where all the empty semantics items are added to the chart? Does
>>> it simply not work if you have no trigger rules? (I admit not having tried
>>> this for years.)
>>>
>>> However, if not, it seems to me that the extract from a corpus technique
>>> could work with small grammars assuming you've got a suitable set of test
>>> sentences before you start to generate. i.e., you'd parse those and
>>> accumulate trigger rules automatically from the parsed set, repeating as
>>> you expand the grammar. It doesn't matter if the trigger rules are very
>>> liberal, after all.
>>>
>>> Ann
>>>
>>> On 10/02/2016 23:14, Emily M. Bender wrote:
>>>
>>> The tdl output is helpful to the extent that it shows people what the
>>> value of TRIGGER should
>>> be, but that's about it. It's particularly unhelpful when the trigger
>>> rules are actually there... Also,
>>> learning trigger rules from parsed/treebanked data sounds interesting,
>>> but won't help at all
>>> in the case of starter grammars, which we *do* want to be able to
>>> generate.
>>>
>>> Emily
>>>
>>> On Wed, Feb 10, 2016 at 3:00 PM, Ann Copestake < <aac10 at cam.ac.uk>
>>> aac10 at cam.ac.uk> wrote:
>>>
>>>> Hmm - does anyone find the TDL output for the trigger rules helpful?
>>>> because, having looked at the code, I would prefer to remove that facility
>>>> completely unless it has support, since it's hardwiring type and feature
>>>> names into the code. i.e., I would rather go back to the original
>>>> behaviour which meant that warning messages were output (if there were no
>>>> appropriate existing trigger rules) without the TDL being suggested. I
>>>> believe oe may feel the same way.
>>>>
>>>> The trigger rule mechanism is a mess, in fact. Learning trigger rules
>>>> from parsed/treebanked data is feasible, but too big a project for me to
>>>> take on.
>>>>
>>>> Ann
>>>>
>>>>
>>>> On 10/02/2016 18:47, Dan Flickinger wrote:
>>>>
>>>> Hi Emily -
>>>>
>>>>
>>>> I ran into this behavior too when doing the SWB-oriented grammars for
>>>> the grammar engineering course I taught with Tom last quarter. The culprit
>>>> turns out to be the function index-lexicon(), which right at its end
>>>> cheerfully emits those warning/advice messages for all semantically empty
>>>> entries regardless of whether trigger rules have been defined. Since the
>>>> same shortcoming is repeated in the separate function reindex-lexicon(), it
>>>> proved to be easier for me to correct this by changing the function
>>>> make-trigger-tdl() which they both call, so that the global
>>>> mt::*transfer-triggers* is checked before emitting the warning for each
>>>> semantically empty lexical entry. Here is the patched version of this
>>>> function analogous to what I added to my grammars' user-fns.lsp file:
>>>>
>>>>
>>>> (defun make-trigger-tdl (empty-semantics-lexical-entries)
>>>> (let ((empty-no-trigger-entries
>>>> (loop for id in empty-semantics-lexical-entries
>>>> unless (or #+:mt
>>>> (gethash id mt::*transfer-triggers*)
>>>> nil)
>>>> collect id)))
>>>> (loop for x in empty-no-trigger-entries
>>>> do
>>>> (format t "~%~%~a_gr := generator_rule &
>>>> [ CONTEXT.RELS <! [ PRED \"non_existing_rel\" ] !>,
>>>> FLAGS.TRIGGER \"~a\" ]."
>>>> (string-downcase x)
>>>> (string-downcase x)))))
>>>>
>>>>
>>>> I expect that Ann or Stephan could see a more elegant way to achieve
>>>> this effect, but this patch might be a useful temporary expedient.
>>>>
>>>> Dan
>>>>
>>>>
>>>> ------------------------------
>>>> *From:* developers-bounces at emmtee.net <developers-bounces at emmtee.net>
>>>> <developers-bounces at emmtee.net> on behalf of Emily M. Bender
>>>> <ebender at uw.edu><ebender at uw.edu> <ebender at uw.edu>
>>>> *Sent:* Wednesday, February 10, 2016 7:43 AM
>>>> *To:* developers
>>>> *Subject:* [developers] Trigger rules still being requested
>>>>
>>>> Dear all,
>>>>
>>>> In the Matrix derived grammars, we have the following in lkb/script:
>>>>
>>>> ;;;
>>>> ;;; SSH 2012-03-27 This invokes trigger rules for semantically empty
>>>> ;;; lexical entries. The trigger rules themselves should be in
>>>> ;;; trigger.mtr in the grammar directory. The documentation on trigger
>>>> ;;; rules: <http://moin.delph-in.net/LkbGeneration>
>>>> <http://moin.delph-in.net/LkbGeneration>http://moin.delph-in.net/
>>>> LkbGeneration
>>>> ;;;
>>>> ;;; SSH 2013-05-23 The semi.vpm file needs to be loaded *before* the
>>>> ;;; trigger.mtr file in lkb/script for correct interaction.
>>>> ;;;
>>>>
>>>> (mt:read-transfer-rules
>>>> (list
>>>> (lkb-pathname (parent-directory) "trigger.mtr"))
>>>> "Generation trigger rules"
>>>> :filter nil :task :trigger :recurse nil :edges 200 :subsume nil)
>>>>
>>>> ;;;
>>>> ;;; Matrix-derived grammars often have stable enough semantic
>>>> ;;; representations that the grammar can usefully be tested
>>>> ;;; by generating from them. The function index-for-generator()
>>>> ;;; must be called for generation to be enabled. In grammars with
>>>> ;;; small lexica, this takes a trivial amount of time. If
>>>> ;;; generation is not being used regularly, and the indexing
>>>> ;;; is taking too long, comment out the following.
>>>> index-for-generator()
>>>> ;;; can also be run from the expanded LKB top menu, under
>>>> ;;; Generate.
>>>> ;;;
>>>>
>>>> (index-for-generator)
>>>>
>>>> It is my understanding that (index-for-generator) is what is behind the
>>>> messages
>>>> suggesting trigger rules for semantically empty lexical entries, but
>>>> even though
>>>> we call it after loading the trigger rules, we still get messages such
>>>> as the following:
>>>>
>>>>
>>>>
>>>> Is there something else we're supposed to do so that we only see those
>>>> messages
>>>> when an entry truly lacks a trigger rule?
>>>>
>>>> Thanks,
>>>> Emily
>>>>
>>>> --
>>>> Emily M. Bender
>>>> Professor, Department of Linguistics
>>>> Check out CLMS on facebook! <http://www.facebook.com/uwclma>
>>>> <http://www.facebook.com/uwclma>http://www.facebook.com/uwclma
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Emily M. Bender
>>> Professor, Department of Linguistics
>>> Check out CLMS on facebook! <http://www.facebook.com/uwclma>
>>> http://www.facebook.com/uwclma
>>>
>>>
>>>
>>>
>>
>>
>> --
>> Emily M. Bender
>> Professor, Department of Linguistics
>> Check out CLMS on facebook! http://www.facebook.com/uwclma
>>
>>
>>
>
>
> --
> Emily M. Bender
> Professor, Department of Linguistics
> Check out CLMS on facebook! http://www.facebook.com/uwclma
>
--
Emily M. Bender
Professor, Department of Linguistics
Check out CLMS on facebook! http://www.facebook.com/uwclma
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