The Tor Browser / file revision

 // Copyright 2009 the Sputnik authors.  All rights reserved.

 // This code is governed by the BSD license found in the LICENSE file.

 /**

  * The result of an addition is determined using the rules of IEEE 754 double-precision arithmetics

  *

  * @path ch11/11.6/11.6.1/S11.6.1_A4_T2.js

  * @description The sum of two infinities of opposite sign is NaN

  */

 //CHECK#1

 if (isNaN(Number.POSITIVE_INFINITY + Number.NEGATIVE_INFINITY) !== true ) {

   $ERROR('#1: Infinity + -Infinity === Not-a-Number. Actual: ' + (Infinity + -Infinity));

 }

 //CHECK#2

 if (isNaN(Number.NEGATIVE_INFINITY + Number.POSITIVE_INFINITY) !== true ) {

   $ERROR('#2: -Infinity + Infinity === Not-a-Number. Actual: ' + (-Infinity + Infinity));

 }