[rules-users] Change in eval mvel syntax from 5.1 to 5.3

I have been using 5.1 for some time and am looking to upgrade. I have found that, where in 5.1, I used to be able to write $jd: JobDetails( eval ( $t = ["MTSURVEY", "MTINSTALL", "MTEXCHANGE", "MTMAINT"]; !($t contains getJobType(businessArea, templateJobId) )) ) However, in 5.3.1 this now produces a syntax error as follows:- [CheckJobType] [ERR 101] Line 9:9 no viable alternative at input '$t' in rule "CheckJobType" [CheckJobType] Parser returned a null Package I have found that I have to now code the condition as follows:- $jd: JobDetails( eval (!(["MTSURVEY", "MTINSTALL", "MTEXCHANGE", "MTMAINT"] contains getJobType(businessArea, templateJobId) )) ) It is a relatively minor thing but I am curious as to why I should have to recode this. What has changed to cause me to do this? What other incompatibilities exist? Chris