NAME
	IEEESPAcos -- compute the arc cosine of a number

   SYNOPSIS
	  x   = IEEESPAcos(  y  );
	d0	           d0

	float	x,y;

   FUNCTION
	Compute arc cosine of y in IEEE single precision

   INPUTS
	y - IEEE single precision floating point value

   RESULT
	x - IEEE single precision floating point value

   BUGS

   SEE ALSO
	IEEESPCos(), IEEESPAtan(), IEEESPAsin()