Complex arg-trig functions

[Stephen Montgomery-Smith]

On 09/13/2012 07:55 AM, Bruce Evans wrote:

> % -        /* casinh(NaN + I*inf) = inf + I*NaN */
> % +        /* casinh(NaN + I*+-Inf) = +-Inf + I*NaN (sign optional) */

How much do you want the "sign optional" put into the comments.  This 
will have to be done in lots of places.


One more thing - I made a mistake in the comments for FOUR_SQRT_MIN.  It 
should read:

FOUR_SQRT_MIN = 0x1p-509, /* greater than 4 * sqrt(DBL_MIN) */

that is, "greater" not "less".