export * from "fp-ts/Eq";
import * as Eq from "fp-ts/Eq";
import { Refinement } from "fp-ts/Refinement";
export declare function combine<A, B>(a: Eq.Eq<A>, b: Eq.Eq<B>): Eq.Eq<A & B>;
export declare function eqNullable<T>(eq: Eq.Eq<T>): Eq.Eq<T | null | undefined>;
export type UnionEqBuilder<U, E extends U> = [U] extends [E] ? Eq.Eq<U> : {
    with: <T1 extends Exclude<U, E>>(ref: Refinement<Exclude<U, E>, T1>, eq: Eq.Eq<T1>) => UnionEqBuilder<U, E | T1>;
};
export declare function union<U>(): UnionEqBuilder<U, never>;