priorities in sitemap xml files

I have assigned priorities to the different URL's in my sitemap.xml file
according to their relative importance to each other. Some say it doesn't
really make a difference, but I had fun doing it.
The reason I'm posting is because I am a little confused about the priority
for the home page. It is listed twice, once as a domain and once as the
index page in the root domain.
Will it screw things up if I assign a priority of 1.0 for both listings for
the homepage, that is for
www.TheBicyclingGuitarist.net/ and for
www.TheBicyclingGuitarist.net/index.htm ?

I assigned 0.9 to the index pages of the most important sections of my web
site, 0.8 and less to other pages that have content I favor in order of
importance. I try to "balance" the priorities by having equal numbers of 0.1
pages as 0.9, equal numbers of 0.2 pages as 0.8, etc.

So I'm asking if there is some type of algorithm the spiders use that will
have the math screwed up if I list the homepage priority as 1.0 ... Does
anyone KNOW or have any ideas on this subject? thanks

Assigning the priorities to the sitemap.xml inspired me to create a
"favorites" page of what *I* like best about my web site. It is at
http://www.TheBicyclingGuitarist.net.../favorites.htm

have fun