define([], function() {

  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
  var undefined;

  /**
   * Subtract two numbers.
   *
   * @static
   * @memberOf _
   * @category Math
   * @param {number} minuend The first number in a subtraction.
   * @param {number} subtrahend The second number in a subtraction.
   * @returns {number} Returns the difference.
   * @example
   *
   * _.subtract(6, 4);
   * // => 2
   */
  function subtract(minuend, subtrahend) {
    var result;
    if (minuend !== undefined) {
      result = minuend;
    }
    if (subtrahend !== undefined) {
      result = result === undefined ? subtrahend : (result - subtrahend);
    }
    return result;
  }

  return subtract;
});