import { type Inline, type Style } from '@mdgate/document';
/** Tri-state style delta used during cascade resolution. */
export interface StyleDelta {
    bold: boolean | undefined;
    italic: boolean | undefined;
    strike: boolean | undefined;
    code: boolean | undefined;
}
export declare function emptyDelta(): StyleDelta;
/** Overlay `child` on `base`: an explicit child value wins; unset inherits. */
export declare function mergeDelta(base: StyleDelta, child: StyleDelta): StyleDelta;
export declare function applyDelta(delta: StyleDelta, base: Style): Style;
export declare function resolveDelta(delta: StyleDelta): Style;
export declare function deltasEqual(a: StyleDelta, b: StyleDelta): boolean;
/**
 * Drop from every run the emphasis `base` already carries. A heading style
 * defines its own typography, so its runs should carry only what they add
 * beyond it.
 */
export declare function rebaseEmphasis(inlines: Inline[], base: Style): void;