Dump special floating point operators

[ZY.Zhou]

Andrei Alexandrescu Wrote:
> Sorry. So a !>= b is indeed semantically equivalent with isnan(a) || 
> isnan(b) || a < b. However, if I read the table at 
> http://www.digitalmars.com/d/2.0/expression.html#RelExpression 
> correctly, !(a >= b) would throw if either is NaN.
> 

But there is a note under that table:

> "Exception" means the Invalid Exception is raised if one of the 
> operands is a NAN. It does not mean an exception is thrown. 
> Invalid Exception can be checked using the functions in std.c.fenv.

So I don't feel any difference between !(a>=b) and a!>=b