NaN does not equal NaN(swizec.com)

    var determineLater; // undefined
    var blah = 5;
    blah += determineLater; // blah is now NaN

  val > 3

  not (val <= 3)

    #include <stdio.h>

    int main()
    {
	float a = 1. / 0;
	float b = 2. / 0;

 	printf("%f == %f ? %d\n", a, b, a == b);
        return 0;
    }

    inf == inf ? 1

    #include <stdio.h>

    int main()
    {
	float a = 0. / 0;
	float b = a;

 	printf("%f == %f ? %d\n", a, b, a == b);
        return 0;
    }

    nan == nan ? 0