import { Ctx } from "../../ctx";
import { Core } from "../../core";
import { Value } from "../../value";
import { Solution } from "../../solution";
import { Closure } from "../closure";
import { ReadbackEtaExpansion } from "../../value";
export declare class SigmaValue extends Value implements ReadbackEtaExpansion {
    car_t: Value;
    cdr_t_cl: Closure;
    constructor(car_t: Value, cdr_t_cl: Closure);
    readback(ctx: Ctx, t: Value): Core | undefined;
    readback_eta_expansion(ctx: Ctx, value: Value): Core;
    unify(solution: Solution, that: Value): Solution;
}