The notation is hard to read.  I think that maybe I would have 
understood what was going on if it was written in MathML.  I found 
http://biokyb.dyndns.org/aknet/cg/ray_sphere_intersect_algebraic/ this 
workout of the problem, and it pretty much matched my own calculations, 
so I decided the book was wrong, and that the POV-Ray code matches what 
is in the link I found.  I'm still not sure if the psudocode explanation 
makes sense.  But I found an overlooked math fact that leads to multiple 
optimizations  If D is actually a unit vector like it is supposed to be 
then D.D has to be "1".  Thus...

The line starting with #local D2 can be removed.  The next line will now 
  be.

#local SQ = DV*DV - (vdot(V,V) - R*R);

And

#local T2 = (-DV-SQ);

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