import type { PropFormula } from "../../../models";
/**
 * Applies the conjunction introduction rule.
 *
 * Given two formulas A and B, it returns two conjunctions: (A ∧ B) and (B ∧ A)
 *
 * @param formulas An array of propositional formulas.
 * @returns {[PropFormula, PropFormula]} A tuple containing the two inferred formulas.
 * @throws {Error} if the formulas do not satisfy conjunction introduction conditions.
 */
export declare function conjunctionIntroduction(formulas: PropFormula[]): [PropFormula, PropFormula];