/**
 * Base class for all parts of a grammar (terminal symbols and non-terminal symbols).
 * Holds the name of the part and the follow parts of the part.
 *
 * See:
 * * {@link NTS}
 * * {@link TS}
 */
export declare abstract class Sym {
    readonly name: string;
    readonly id: number;
    constructor(name: string, id?: number);
    toString(): string;
    equals(other: Sym): boolean;
    /**
     * Returns true if the symbol is a terminal symbol.
     * @returns true if the symbol is a literal or a lower case identifier
     */
    isTS(): boolean;
}