/**
 * LaTeX → MathML (MathLive) → OMML (mathml2omml-plus) for native PowerPoint equations.
 * No hand-rolled math grammar — conversion is entirely library-based.
 */
/** Drop every character that cannot appear in an XML 1.0 document. */
export declare function stripXmlIllegalChars(text: string): string;
/**
 * Well-formedness check mirroring the one pptxgenjs runs on `options.omml`
 * (strict XML 1.0 via `@rgrove/parse-xml` around a synthetic root). Returns
 * the first problem, or null when the fragment is safe to embed.
 */
export declare function validateOmmlFragment(omml: string): string | null;
export interface OmmlRunStyle {
    /** CSS/hex color applied to every math glyph run and control (vinculum, …). */
    color?: string;
    /** Font size in points (`a:rPr sz` is hundredths of a point). */
    fontSizePt?: number;
}
/**
 * Stamp `a:rPr` (color / size) onto every `m:r` and `m:ctrlPr` in an OMML
 * fragment. pptxgenjs embeds OMML as opaque XML and does not propagate the
 * surrounding text-run `options.color`, so contrast-fixed (and user-styled)
 * equation colors must be written into the math markup itself.
 */
export declare function applyOmmlRunStyle(omml: string, style: OmmlRunStyle): string;
/** Ensure MathLive is loaded so sync conversion can run during PPTX export. */
export declare function prepareLatexToOmml(): Promise<void>;
/**
 * Convert a LaTeX expression to an OMML `<m:oMath>…</m:oMath>` string.
 */
export declare function latexToOmml(latex: string): Promise<string>;
/**
 * Sync conversion — MathLive must already be loaded via {@link prepareLatexToOmml}.
 * Returns null when conversion fails (caller falls back to plain LaTeX text).
 */
export declare function tryLatexToOmmlSync(latex: string): string | null;