Question

I’d like to declare a global variable that is scoped to only my rules file.
For example: variable $reUseMe is only declared once.

rule 1

$reUseMe : POJO(val = 1)
//other conditions

rule 2

$reUseMe > val

Answer 1

There are no scoped global variables, but in some cases rule inheritance helps.

rule "Rule 1"
  when
    $reUseMe :POJO( val == 1 )
  then
end

rule "Rule 2" extends "Rule 1"
  when
    # You can use the variables from Rule 1
    POJO( val > $reUseMe.val ) 
  then
end

Only LHS is added. RHS from Rule 1 is ignored in Rule 2.