# $EPIC: atanh.txt,v 1.3 2006/08/21 01:55:33 sthalik Exp $
Returns the inverse hyperbolic tangent of <number>.
If the <number> argument is omitted the empty string is returned.
As always, the return value is limited to 6 decimal places.
As always, DOM or RANGE means there was an error.
The inverse hyperbolic tangent of an angle