Documentation

Linglib.Semantics.Polarity.Licensing

Polarity licensing #

A context licenses a polarity item when the licenser it places over the item carries the strength of negation the item needs, after Ladusaw, Zwarts and Gajewski; when it is a modal licenser licensing free choice and the item is a free choice item, after Kadmon and Landman and Chierchia; or when it is a question and the item a weak negative polarity item, after van Rooy. It anti-licenses an item when its licenser holds outright the strength that blocks it, after van der Wouden and Szabolcsi. What each context carries is a theorem about the operators it denotes (Semantics/Polarity/LicensingContext.lean), so what it licenses follows from what it means, and each fragment checks the theory against the contexts its entries are attested and excluded in.

Main declarations #

Main results #

References #

A context licenses an item when its licenser carries the item's licensor, licenses free choice and the item is a free choice item, or licenses by relevance and the item is a weak negative polarity item.

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    A context anti-licenses an item when its licenser holds outright the strength that blocks the item.

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      A context admits an item when it licenses the item, if the item needs licensing, and does not anti-license it.

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        theorem PolarityItem.Licenser.admits_iff_licenses {L : Licenser} {e : PolarityItem} (h : e.antiLicensor = none) (he : e.IsNPI ∨ e.IsFCI) :
        L.Admits e ↔ L.Licenses e

        The profiles of the licensers #

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        instance PolarityItem.Licenser.instDecidablePredAdmitsOfLicensesOfAntiLicenses {L : Licenser} [DecidablePred L.Licenses] [DecidablePred L.AntiLicenses] :
        DecidablePred L.Admits
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        The theory #

        theorem PolarityItem.Licenser.licenses_iff_carries {L : Licenser} {e : PolarityItem} {r : DEStrength} (he : e.licensor = some r) (hr : r ≠ DEStrength.weak) (hf : ¬e.IsFCI) :
        L.Licenses e ↔ L.Carries r

        An item needing a strength above weak, and not a free choice item, is licensed exactly by the contexts whose licenser carries that strength.

        A non-trivial classical context blocks the positive polarity items of a class exactly where it licenses the negative polarity items of that class (the mirror image of [vdW97]'s (181)).

        theorem PolarityItem.Licenser.Licenses.of_licensor_le {L : Licenser} {e e' : PolarityItem} {r r' : DEStrength} (he : e.licensor = some r) (he' : e'.licensor = some r') (hr : r' ≤ r) (hf : e.IsFCI → e'.IsFCI) (hl : L.Licenses e) :

        A context licensing an item licenses every item with a weaker licensor that is a free choice item if the first is.

        Deciding licensing at the named contexts #

        What a named context licenses and anti-licenses is decided by the item, through the lemmas above.

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        Admission at a named context is decided without computing its licenser.

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        Clausal negation blocks every positive polarity item, since its licenser holds the top of the chain ([vdW97]'s (169)).