c/numeric/complex/casin

@1-3@ Computes the complex arc sine of with branch cuts outside the interval $[−1,+1]$ along the real axis. @4@ Type-generic macro: If has type,  is called. if has type,  is called, if  has type ,  is called. If is real or integer, then the macro invokes the corresponding real function. If is imaginary, then the macro invokes the corresponding real version of the function asinh, implementing the formula, and the return type of the macro is imaginary.

Return value
If no errors occur, complex arc sine of is returned, in the range of a strip unbounded along the imaginary axis and in the interval $[−π/2; +π/2]$ along the real axis.

Errors and special cases are handled as if the operation is implemented by