K 10
svn:author
V 4
tijl
K 8
svn:date
V 27
2015-06-15T20:16:53.228362Z
K 7
svn:log
V 236
Fix some exceptional cases where the sign of the result is unspecified
but must still satisfy csinh(conj(z)) == conj(csinh(z)) and csinh(-z) ==
-csinh(z).  This allows eliminating two negations from csin(z).

In collaboration with:	bde

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