User:Magnap/Inquisitive Semantics Proposal: Difference between revisions

→‎TODO proposal details: Split completeness out into its own proposal
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An important thing to bear in mind about inquisitive semantics is that it does not give us a Boolean algebra, but only a Heyting algebra, meaning that <math>\neg\neg\text{P} = \text{P}</math> is not guaranteed. In fact, the non-inquisitive projection operator <math>\lambda \text{P}. !\text{P}</math>, which collapses all the alternatives of a proposition into just one (called <math>\text{info}\left(\text{P}\right)</math>) which contains them all, thus keeping the assertion the same but ensuring that no question is asked, ''is'' just <math>\lambda \text{P}. \neg\neg\text{P}</math>. Another important operator is the non-informative projection operator <math>\lambda \text{P}. ?\text{P} = \lambda \text{P}. \text{P} \lor \neg\text{P}</math>, which ensures that a proposition does not assert anything by adding an alternative which covers all worlds that would otherwise have been ruled out. Finally (TODO source! well tbf I made it up initially but it ''is'' attested, at least in one presentation by one of the inqsem guys) there's the presupposition operator <math>\lambda \text{P}. ;\text{P} = \lambda \text{P}. \left(\text{P} | \text{info}\left(\text{P}\right)\right)</math>.
An important thing to bear in mind about inquisitive semantics is that it does not give us a Boolean algebra, but only a Heyting algebra, meaning that <math>\neg\neg\text{P} = \text{P}</math> is not guaranteed. In fact, the non-inquisitive projection operator <math>\lambda \text{P}. !\text{P}</math>, which collapses all the alternatives of a proposition into just one (called <math>\text{info}\left(\text{P}\right)</math>) which contains them all, thus keeping the assertion the same but ensuring that no question is asked, ''is'' just <math>\lambda \text{P}. \neg\neg\text{P}</math>. Another important operator is the non-informative projection operator <math>\lambda \text{P}. ?\text{P} = \lambda \text{P}. \text{P} \lor \neg\text{P}</math>, which ensures that a proposition does not assert anything by adding an alternative which covers all worlds that would otherwise have been ruled out. Finally (TODO source! well tbf I made it up initially but it ''is'' attested, at least in one presentation by one of the inqsem guys) there's the presupposition operator <math>\lambda \text{P}. ;\text{P} = \lambda \text{P}. \left(\text{P} | \text{info}\left(\text{P}\right)\right)</math>.
TODO explain how adding presupposition to InqB would work in more detail?
Since this proposal is, after all, suggesting that we base the formal language of our semantics on InqB+presupposition.


===Examples===
===Examples===
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The complementizer {{t|ma}} will gain semantics, specifically <math>\lambda \text{P}. ?!P</math>.
The complementizer {{t|ma}} will gain semantics, specifically <math>\lambda \text{P}. ?!P</math>.
We will need to add a new phrase to the grammar, the completeness phrase, TODO describe the completeness operators. However, it will usually have a null head, the incompleteness operator (which I'm pretty sure just does nothing?).


We'll probably want prefixes that apply to quantifiers and apply one of the following to the result of applying the quantifier (in other words, applying them outside the quantifier): <math>!</math>, <math>;</math>, <math>?</math>, <math>?!</math>.
We'll probably want prefixes that apply to quantifiers and apply one of the following to the result of applying the quantifier (in other words, applying them outside the quantifier): <math>!</math>, <math>;</math>, <math>?</math>, <math>?!</math>.
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Finally, the {{t|hí}} problem: if we want to remain backwards compatible with existing Toaq Delta wh-questions, we must assign it a meaning. Unfortunately, whether or not wh-questions generate presuppositions (in our notation, whether {{t|hí}} means <math>;\exists</math> or <math>?\exists</math>) is a highly contested issue that we would be forced to pick a side on...
Finally, the {{t|hí}} problem: if we want to remain backwards compatible with existing Toaq Delta wh-questions, we must assign it a meaning. Unfortunately, whether or not wh-questions generate presuppositions (in our notation, whether {{t|hí}} means <math>;\exists</math> or <math>?\exists</math>) is a highly contested issue that we would be forced to pick a side on...


We might also want new or different connectives, or at least to give specific denotations for them. For example, we probably want {{t|ró}} to create two alternatives, which means we'd want it to be <math>\left(P \land \neg\text{Q}\right) \lor \left(\neg\text{P} \land{} \text{Q}\right)</math>. Other potentially quite useful connectives are (sometimes writing them out in a more verbose way than necessary to make their alternatives clearer):
We might also want new or different connectives, or at least to give specific denotations for them. For example, we probably want {{t|ró}} to create two alternatives, which means we'd want it to be <math>\left(P \land \neg\text{Q}\right) \lor \left(\neg\text{P} \land{} \text{Q}\right)</math>.
Other potentially quite useful connectives are (sometimes writing them out in a more verbose way than necessary to make their alternatives clearer):
* <math>?\text{P} \land{} ?\text{Q}</math> (one or the other or both or neither)
* <math>?\text{P} \land{} ?\text{Q}</math> (one or the other or both or neither)
* <math>\left(P \land \text{Q}\right) \lor \left(P \land \neg\text{Q}\right) \lor \left(\neg\text{P} \land \text{Q}\right)</math> (one or the other or both)
* <math>\left(P \land \text{Q}\right) \lor \left(P \land \neg\text{Q}\right) \lor \left(\neg\text{P} \land \text{Q}\right)</math> (one or the other or both)
* <math>\left(P \land \neg\text{Q}\right) \lor \left(\neg\text{P} \land \text{Q}\right) \lor \left(\neg\text{P} \land \neg\text{Q}\right)</math> (one or the other or neither)
* <math>\left(P \land \neg\text{Q}\right) \lor \left(\neg\text{P} \land \text{Q}\right) \lor \left(\neg\text{P} \land \neg\text{Q}\right)</math> (one or the other or neither)
And so many more, this is rich bikeshedding territory and luckily more can easily be added later.
And so many more, this is rich bikeshedding territory and luckily more can easily be added later.
Another concern is {{t|rí}} which is weird in the refgram, allowing you to answer with a connective!? I think we should fix that one up somehow. We almost certainly need a denotation that generates a non-informative proposition and doesn't presuppose anything, but there are many of those. Two reasonably intuitive options would be <math>?\left(\text{P} \lor \text{Q}\right)</math> and <math>?\text{P} \land{} ?\text{Q}</math>.
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