That worked great.  Here's what I put into MapleTA's algorithm:

$z95=maple("with(Statistics):Quantile(Normal(0,1),.95)");
$p95=maple("with(Statistics):CDF(Normal(0,1),$z95)");

and it did what i expected.  (the erf formulation didn't work, im not sure why, but i dont really need it now anyway.)

Yes this Quantile is the function I needed!

The MapleTA algorithm, which seems to be working well, is, for instance:

 $x=maple("with(Statistics):Quantile(Normal(0,1),.5)")
$x1=maple("with(Statistics):Quantile(Normal(0,1),.6)")

I can then use $x1 and $x2 in the statement of the question and in the answer.

Does anyone know the name of the Gaussian CDF itself (not the inverse, which is this Quantile function?)  So for instance GaussianCDF(0)=.5?

Thanks so much for your help so far.