If Type(x) is String, then return true if x and y are exactly the same sequence of characters (same length and same characters in corresponding positions). Otherwise, return false.
If Type(x) is Number, then If x is NaN, return false. If y is NaN, return false. If x is the same Number value as y, return true. If x is +0 and y is −0, return true. If x is −0 and y is +0, return true. Return false.