import { Arbitrary } from './definition/Arbitrary';
/**
 * For mutually recursive types
 *
 * @example
 * ```typescript
 * const { tree } = fc.letrec(tie => ({
 *   tree: fc.oneof(tie('node'), tie('leaf'), tie('leaf')),
 *   node: fc.tuple(tie('tree'), tie('tree')),
 *   leaf: fc.nat()
 * })); // tree is 1 / 3 of node, 2 / 3 of leaf
 * ```
 *
 * @param builder - Arbitraries builder based on themselves (through `tie`)
 */
export declare function letrec<T>(builder: (tie: (key: string) => Arbitrary<unknown>) => {
    [K in keyof T]: Arbitrary<T[K]>;
}): {
    [K in keyof T]: Arbitrary<T[K]>;
};