Enum ModalFlavor 

pub enum ModalFlavor {
    Root,
    Epistemic,
    Evidential,
    Bouletic,
}

Modal flavor affecting scope interpretation.

The distinction between root and epistemic modals affects quantifier scope: root modals scope under quantifiers (de re), while epistemic modals scope over quantifiers (de dicto).

Variants

Root

Root modals express ability, obligation, or circumstantial possibility. Verbs: can, must, should, shall, could, would. Scope: NARROW (de re) — modal attaches inside quantifier scope. Example: “Every student can solve this” = ∀x(Student(x) → ◇Solve(x, this))

Epistemic

Epistemic modals express possibility or deduction based on evidence. Verbs: might, may (epistemic readings). Scope: WIDE (de dicto) — modal wraps the entire quantified formula. Example: “A student might win” = ◇∃x(Student(x) ∧ Win(x))

Evidential

Evidential modality marks an evidence source without asserting the complement: raising verbs seem/appear/look (§4.3). Frame: serial, non-reflexive — Seem(⟨P⟩) does not entail P. Example: “John seems happy” = Seem(⟨Happy(john)⟩)

Bouletic

Bouletic modality quantifies over preference-ideal worlds: wishes (§1.2 optatives) and directives (§1.4 imperatives). Frame: serial — the wished/commanded content is never entailed.

Trait Implementations

impl Clone for ModalFlavor

fn clone(&self) -> ModalFlavor

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ModalFlavor

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for ModalFlavor

fn eq(&self, other: &ModalFlavor) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ModalFlavor

impl Eq for ModalFlavor

impl StructuralPartialEq for ModalFlavor