import { $, HKT } from '.';
export declare type CartesianInstances = keyof typeof Cartesian;
export interface Cartesian<F extends HKT> {
    product<A, B>(fa: $<F, A>, fb: $<F, B>): $<F, [A, B]>;
}
export declare namespace Cartesian {
}
export declare function product<F extends CartesianInstances, A, B>(fa: $<F, A>, fb: $<F, B>): $<F, [A, B]>;