I would like to extract the rules surrounding how commissions for sales reps are
calculated when they sell a loan product. While it will increase in complexity,
here's an example XML file:
(Ignore the periods - I added them to format this HTML posting)

<MonthlyLoans>
. <Loan>
... <Rep>Sally</Rep>
... <State>NC</State>
... <Amount>150000</Amount>
... <LoanType>HELOC</LoanType>
. </Loan>
. <Loan>
... <Rep>Joe</Rep>
... <State>SC</State>
... <Amount>150000</Amount>
... <LoanType>Construction</LoanType>
. </Loan>
</MonthlyLoans>

How would the Rules file need to be coded to calculate a Commission where the
loan sold in 'NC' would receive 0.5% while the Commission sold in SC would
receive 0.4%?

Also, the tutorial for coding in C# is Great. But, where can I find
documentation regarding tags, parameters, etc for the Rules (.xr) file?