text: 'use strict';
  
  var nearlyEqual = require('../../utils/number').nearlyEqual;
  var bigNearlyEqual = require('../../utils/bignumber/nearlyEqual');
  
  function factory (type, config, load, typed) {
  
    var matrix = load(require('../../type/matrix/function/matrix'));
  
    var algorithm03 = load(require('../../type/matrix/utils/algorithm03'));
    var algorithm07 = load(require('../../type/matrix/utils/algorithm07'));
    var algorithm12 = load(require('../../type/matrix/utils/algorithm12'));
    var algorithm13 = load(require('../../type/matrix/utils/algorithm13'));
    var algorithm14 = load(require('../../type/matrix/utils/algorithm14'));
  
    var latex = require('../../utils/latex');
  
    /**
     * Test whether two values are unequal.
     *
     * The function tests whether the relative difference between x and y is
     * larger than the configured epsilon. The function cannot be used to compare
     * values smaller than approximately 2.22e-16.
     *
     * For matrices, the function is evaluated element wise.
     * In case of complex numbers, x.re must unequal y.re, or x.im must unequal y.im.
     *
     * Values `null` and `undefined` are compared strictly, thus `null` is unequal
     * with everything except `null`, and `undefined` is unequal with everying
     * except. `undefined`.
     *
     * Syntax:
     *
     *    math.unequal(x, y)
     *
     * Examples:
     *
     *    math.unequal(2 + 2, 3);       // returns true
     *    math.unequal(2 + 2, 4);       // returns false
     *
     *    var a = math.unit('50 cm');
     *    var b = math.unit('5 m');
     *    math.unequal(a, b);           // returns false
     *
     *    var c = [2, 5, 1];
     *    var d = [2, 7, 1];
     *
     *    math.unequal(c, d);           // returns [false, true, false]
     *    math.deepEqual(c, d);         // returns false
     *
     *    math.unequal(0, null);        // returns true
     * See also:
     *
     *    equal, deepEqual, smaller, smallerEq, larger, largerEq, compare
     *
     * @param  {number | BigNumber | Fraction | boolean | Complex | Unit | string | Array | Matrix | undefined} x First value to compare
     * @param  {number | BigNumber | Fraction | boolean | Complex | Unit | string | Array | Matrix | undefined} y Second value to compare
     * @return {boolean | Array | Matrix} Returns true when the compared values are unequal, else returns false
     */
    var unequal = typed('unequal', {
      
      'any, any': function (x, y) {
        // strict equality for null and undefined?
        if (x === null) { return y !== null; }
        if (y === null) { return x !== null; }
        if (x === undefined) { return y !== undefined; }
        if (y === undefined) { return x !== undefined; }
  
        return _unequal(x, y);
      },
  
      'Matrix, Matrix': function (x, y) {
        // result
        var c;
  
        // process matrix storage
        switch (x.storage()) {
          case 'sparse':
            switch (y.storage()) {
              case 'sparse':
                // sparse + sparse
                c = algorithm07(x, y, _unequal);
                break;
              default:
                // sparse + dense
                c = algorithm03(y, x, _unequal, true);
                break;
            }
            break;
          default:
            switch (y.storage()) {
              case 'sparse':
                // dense + sparse
                c = algorithm03(x, y, _unequal, false);
                break;
              default:
                // dense + dense
                c = algorithm13(x, y, _unequal);
                break;
            }
            break;
        }
        return c;
      },
  
      'Array, Array': function (x, y) {
        // use matrix implementation
        return unequal(matrix(x), matrix(y)).valueOf();
      },
  
      'Array, Matrix': function (x, y) {
        // use matrix implementation
        return unequal(matrix(x), y);
      },
  
      'Matrix, Array': function (x, y) {
        // use matrix implementation
        return unequal(x, matrix(y));
      },
  
      'Matrix, any': function (x, y) {
        // result
        var c;
        // check storage format
        switch (x.storage()) {
          case 'sparse':
            c = algorithm12(x, y, _unequal, false);
            break;
          default:
            c = algorithm14(x, y, _unequal, false);
            break;
        }
        return c;
      },
  
      'any, Matrix': function (x, y) {
        // result
        var c;
        // check storage format
        switch (y.storage()) {
          case 'sparse':
            c = algorithm12(y, x, _unequal, true);
            break;
          default:
            c = algorithm14(y, x, _unequal, true);
            break;
        }
        return c;
      },
  
      'Array, any': function (x, y) {
        // use matrix implementation
        return algorithm14(matrix(x), y, _unequal, false).valueOf();
      },
  
      'any, Array': function (x, y) {
        // use matrix implementation
        return algorithm14(matrix(y), x, _unequal, true).valueOf();
      }
    });
  
    var _unequal = typed('_unequal', {
  
      'boolean, boolean': function (x, y) {
        return x !== y;
      },
  
      'number, number': function (x, y) {
        return !nearlyEqual(x, y, config.epsilon);
      },
  
      'BigNumber, BigNumber': function (x, y) {
        return !bigNearlyEqual(x, y, config.epsilon);
      },
  
      'Fraction, Fraction': function (x, y) {
        return !x.equals(y);
      },
  
      'Complex, Complex': function (x, y) {
        return !x.equals(y);
      },
  
      'Unit, Unit': function (x, y) {
        if (!x.equalBase(y)) {
          throw new Error('Cannot compare units with different base');
        }
        return unequal(x.value, y.value);
      },
  
      'string, string': function (x, y) {
        return x !== y;
      }
    });
  
    unequal.toTex = '\\left(${args[0]}' + latex.operators['unequal'] + '${args[1]}\\right)';
  
    return unequal;
  }
  
  exports.name = 'unequal';
  exports.factory = factory;
  