import type { PropFormula } from "../../models";
/**
 * Extracts all true sub-formulas from a given propositional formula.
 * This function does not include atomic formulas (Operator.Var) as sub-formulas,
 * nor does it include the input formula itself.
 *
 * @param {PropFormula} formula - The propositional formula to extract sub-formulas from.
 * @returns {PropFormula[]} An array of unique sub-formulas, sorted in evaluation order.
 * @category Converters
 */
export declare function extractPropSubFormulas(formula: PropFormula): PropFormula[];