/**
* Resolves the accessible name for a viewer's overall shadow semantic owner.
*
* A non-empty host `aria-label` already exposes the custom-element host as a named semantic
* owner, so it must not be copied onto a second owner in shadow DOM. An explicitly empty host
* label remains explicit on the shadow owner, while an absent label permits the component's
* localized or property-derived fallback.
*/
export declare function viewerSemanticLabel(host:Element,fallback?:string|null):string|null;
/** Omits a redundant shadow role when a non-empty host label owns the viewer semantics. */
export declare function viewerSemanticRole(host:Element,role:string):string|null;