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.

 /**

  * Operator x - y produces the same result as x + (-y)

  *

  * @path ch11/11.6/11.6.2/S11.6.2_A4_T3.js

  * @description The difference of two infinities of the same sign is NaN

  */

 //CHECK#1

 if (isNaN(Number.POSITIVE_INFINITY - Number.POSITIVE_INFINITY) !== true ) {

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

 }

 //CHECK#2

 if (isNaN(Number.NEGATIVE_INFINITY - Number.NEGATIVE_INFINITY) !== true ) {

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

 }