[Cfp-interest 3053] csinh(x + i y) - G.6.3.5 - 5th bullet point of special cases

[Damian McGuckin]

The special case is mentioned:

 	csinh(x + i * INFINITY) returns NaN + i * NaN for positive finite x

is given.

No mention is made of

 	csinh(x + i * INFINITY) for negative finite x

I think the special case is not limited to positive finite x. I think it 
is simply

 	finite x
or
 	csinh(x + i * INFINITY) returns NaN + i * NaN for finite x

Am I wrong?  See my workings below just in case I have lost it.

Thanks - Damian

Now, if I can abbreviate INFINITY by INF:

For positive x, i.e. x > 0

    csinh(+x + i * INF) = sinh(+x)cos(INF) + i * cosh(+x)sin(INF)
                = S * NaN + i C * NaN (S = sinh(+x), C = cosh(+x))
                = NaN + i * NaN

Let's look at the negative real component case (using the same x > 0)

    csinh(-x + i * INF) = sinh(-x)cos(INF) + i * cosh(-x)sin(INF)
                = -S * NaN + i * C * NaN
                = NaN + i * NaN