[Cfp-interest 3083] csinh(0 + i NaN)

[Damian McGuckin]

G.6.3.5 says

 	csinh(+0 + i NaN) = +/- 0 + i NaN

without a floating point exception.

Taking inverses of both sides says

 	+0 + i NaN = casinh(+/- 0 + i NaN)
or
 	casinh(+/- 0 + i NaN) = +0 + i NaN  ..... (1)

Is this still valid in the presence of a NaN?

I note that, clause G.6.3.2 says

 	casinh(x + i NaN) returns NaN + i NaN

for finite x. A valid finite x of zero, plugged into G 6.3.2, yields

 	casinh(0 + i NaN) = NaN + i NaN  ........ (2)

As Eq(1) != Eq(2), then G.6.3.2 and G.6.3.5 are is disagreement.

Or is there something I am missing here?

Thanks - Damian