Issue extraction

The issue-side observable on discourse states: HasIssue extracts the current issue, a Question W, the way HasCommonGround extracts the common ground. In inquisitive pragmatics the context is an issue and the context set is its informative content; frameworks tracking both projections relate them per instance. How much of the context set an issue's informative content retains is a fact about the framework, not a law: on a commitment space a bipolar question raises an issue and a monopolar question does not (Studies/Krifka2015.lean).

Main definitions

• Discourse.HasIssue: extraction of the current issue from a discourse state.

References

• I. Ciardelli, J. Groenendijk and F. Roelofsen, Inquisitive Semantics (2018)

class Discourse.HasIssue (S : Type u_1) (W : outParam (Type u_2)) : Type (max u_1 u_2)

A discourse state from which the current issue can be extracted.

• toIssue : S → Question W

@[reducible, inline]

abbrev Discourse.HasIssue.settles {S : Type u_1} {W : Type u_2} [HasIssue S W] (i : Set W) (s : S) : Prop

An information state settles a discourse state's issue iff it resolves the extracted Question.

Equations

• Discourse.HasIssue.settles i s = (i ∈ Discourse.HasIssue.toIssue s)

@[instance_reducible]

instance Discourse.instHasIssueQuestion {W : Type u_1} : HasIssue (Question W) W

An issue is its own extraction.

Equations

• Discourse.instHasIssueQuestion = { toIssue := id }