import { Ctx } from "../ctx";
import { Value } from "../value";
export declare abstract class Solution {
    abstract extend(name: string, value: Value): Solution;
    abstract find(name: string): Value | undefined;
    abstract names: Array<string>;
    static logic_var_p(value: Value): boolean;
    static logic_var_name(value: Value): string;
    static get empty(): EmptySolution;
    static empty_p(solution: Solution): solution is EmptySolution;
    static get failure(): FailureSolution;
    static failure_p(solution: Solution): solution is FailureSolution;
    walk(value: Value): Value;
    unify(x: Value, y: Value): Solution;
    unify_or_fail(ctx: Ctx, left: Value, right: Value): Solution;
}
declare class EmptySolution extends Solution {
    names: never[];
    extend(name: string, value: Value): Solution;
    find(name: string): Value | undefined;
}
declare class FailureSolution extends Solution {
    names: never[];
    extend(name: string, value: Value): Solution;
    find(name: string): Value | undefined;
}
export {};