I'm beginner in Jess. I'm trying to compare two variables from a Java class in Jess and trying to execute a rule. I have imported cTNumber and measuredCurrent (both are integer)form a java class called CurrentSignal. Similarly imported vTNumberand measuredVoltage form a java class DERSignal. Now I want to make a rule such that if cTNumber is equal to vTNumber then multiply measuredCurrent and measuredVoltage (Both are double) for calculating power. I'm trying in this way.... (import signals.*) (deftemplate CurrentSignal (declare (from-class CurrentSignal))) (deftemplate DERSignal (declare (from-class DERSignal))) (defglobal ?*CTnumber* = 0) (defglobal ?*VTnumber* = 0) (defglobal ?*VTnumberDER* = 0) (defglobal ?*measuredCurrent* = 0) (defglobal ?*measuredVoltage* = 0) (defglobal ?*measuredVoltageDER* = 0) (defrule Get-CT-Number (CurrentSignal (cTNumber ?m)) (CurrentSignal (measuredCurrent ?c)) => (bind ?*measuredCurrent* ?c) (printout t "Measured Current : " ?*measuredCurrent*" Amps"crlf) (bind ?*CTnumber* ?m) (printout t ?*CTnumber* crlf) ) (defrule Get-DER-Number (DERSignal (vTNumber ?o)) (DERSignal (measuredVoltage ?V)) => (bind ?*measuredVoltageDER* ?V) (printout t "Measured Voltage : " ?*measuredVoltageDER* " V" crlf) (bind ?*VTnumberDER* ?o) (printout t ?*VTnumberDER* crlf) ) (defrule Power-Calculation-DER-signal "Power calculation of DER Bay" (test (= ?*CTnumber* ?*VTnumberDER* )) => (printout t "Total Generation : " (* ?*measuredCurrent* ?*measuredVoltageDER*) crlf) ) But the Total Generation is showing 0. But I tried calculating in Java and it's showing a number. Can anyone please help me to solve this problem. Thank you.