[rules-users] Converting from Java to MVEL dialect

We are experiencing permgen space issues in our test environment and we have decided to convert our rules from the java dialect to MVEL. I'm wondering if anybody knows of a reference that describes the syntactic differences between the two dialects and what steps we need to take in order to convert. For example, a small number of our rules have conditional statements in the right-hand side and we will need to rewrite these I believe. Thanks in advance, Dave