Pricing Precedence

 I would like to know how Oracle uses the precedences in Advance Pricing to calculate what modifier applies and which ones don't.  We currently have the event phase to "precedence" and having a hard time understanding how all the different precedences works within a modifier.  There are three different precedences within a modifier:

1. Header Qualifier Precedence

2. Line Attribute Precedence

3. Line Qualifier Precedence

I would like to know how Oracle Advance Pricing using each one of these precedence to determine which modifiers applies over another modifier.