Bayes rule and joint probability

[elr0d]

I try to understand the following equation but I can not.
I have basic knowledge about Bayes rule and joint probability.
How can we produce this result? I would appreciate any help.

p(R|q,x)/p(NR|q,x)=[p(R|q) / p(NR|q) ] * [p(x|R,q) / p(x|NR,q)]

 

[mathman]

I have some trouble with your equation, since you haven't defined the symbols. Which are random variables, etc.? It looks to me q is irrelevant.