JESS: Accumulating values in a Variable in JESS

Dear All, I need to accumulate the all values obtained by the rules in the same variable, I mean, sum the variable value to another value and storing in the variable. Below you can see my code. However it ovewrites the value and in the end only presents the last value. Could you please help me?

JESS: Working with jess and java variables

Dear All, Could you please inform me how could I transfer jess variables values to java variables and vice versa? Thanks in advance for your help. Regards, Marcelo Alvarenga Pedrosa