/** Linear expression for constraint equations */
export declare class UIExpression {
    /** Constant term */
    constant: number;
    /** Variable coefficients */
    private readonly terms;
    /**
     * @param constant Constant term
     * @param terms Variable-coefficient pairs
     */
    constructor(constant?: number, terms?: [number, number][]);
    /**
     * Creates expression representing a + b.
     * @param a First expression
     * @param b Second expression
     * @returns Sum of expressions
     */
    static plus(a: UIExpression, b: UIExpression): UIExpression;
    /**
     * Creates expression representing a - b.
     * @param a First expression
     * @param b Second expression
     * @returns Difference of expressions
     */
    static minus(a: UIExpression, b: UIExpression): UIExpression;
    /**
     * Adds variable term to expression.
     * @param variableIndex Variable descriptor
     * @param coefficient Coefficient to add
     * @returns This instance for chaining
     */
    plus(variableIndex: number, coefficient: number): this;
    /**
     * Subtracts variable term from expression.
     * @param variableIndex Variable descriptor
     * @param coefficient Coefficient to subtract
     * @returns This instance for chaining
     */
    minus(variableIndex: number, coefficient: number): this;
    /**
     * Multiplies all terms by scalar.
     * @param value Scalar multiplier
     * @returns This instance for chaining
     */
    multiply(value: number): this;
    /**
     * Divides all terms by scalar.
     * @param value Scalar divisor
     * @returns This instance for chaining
     */
    divide(value: number): this;
    /**
     * Checks if expression contains variable term.
     * @param variableIndex Variable descriptor
     * @returns True if variable has term
     */
    hasTerm(variableIndex: number): boolean;
    /**
     * Copies from another expression.
     * @param expression Source expression
     * @returns This instance for chaining
     */
    copy(expression: UIExpression): this;
    /**
     * Creates independent copy.
     * @returns New expression with same content
     */
    clone(): UIExpression;
}