{* *! version 1.0.3  09fep2009}{...}
    {cmd:atanh(}{it:x}{cmd:)}
{p2colset 8 22 26 2}{...}
{p2col: Domain:}-1 to 1{p_end}
{p2col: Range:}-8e+307 to 8e+307{p_end}
{p2col: Description:} returns the inverse hyperbolic tangent
	of {it:x}, {cmd:atanh(}{it:x}{cmd:)} =
	{bind:(1/2){ln(1+{it:x}) - ln(1-{it:x})}}.
	{p_end}
{p2colreset}{...}
