Is "not >" equivalent to "<=" for a double

Question

double a, b = ...;

Are the following C#-statements

!(a > b)

and

a <= b

equivalent or are there any numerical caveats?

Answer 1

They are equivalent if they are standard vanilla double numeric values.

With nullable, NaN, etc, this isn't as clear.

Consider

double? a = null;
double b = 1;

if (!(a > b))
{
   //yes
}
if ((a <= b))
{
   //no
}

Or as Marc Gravell♦ pointed out, the below demonstrates the exact same behaviour, while sticking with pure double:

double a = 42;
double b = double.NaN;