drools rules that requires multiple other rules

I'm new to drools and I've written some rules and they work as expected. However, I can't help but think there is a more concise way of writing these rules.

My situation is that many of the rules have a few similar basic requirements that I'm repeating in each rule. So, for instance, suppose I have the following rules:

rule "Main Valid Message"
  when Account (open && valid)
  then myResults.add(new Message("Your account is valid"))
end

rule "The user owns something Message"
  when Account (ownership.size() >= 1)
  then myResults.add(new Message("You own something"))
end

rule "Eligibility Message"
  when
    Account (open && valid)
    Account (ownership.size() >= 1)
  then myResults.add(new Message("You are eligible"))
end

Is there a way to rewrite the eligibility rule to take advantage of the first two rules instead of duplicating their content?

ANSWER: Using a combination of J Andy's and laune's replies below, I wrote it as follows:

declare IsValid
   account : Account
end

declare OwnsSomething
   account : Account 
end

rule "Main Valid Message"
   when $account : Account (open && valid)
   then 
      myResults.add(new Message("Your account is valid"))
      insertLogical(new IsValid($account));
end

rule "The user owns something Message"
   when $account : Account (ownership.sizeOwnsSomething() >= 1)
   then 
      myResults.add(new Message("You own something"))
      insertLogical(new OwnsSomething($account));
end

rule "Eligibility Message"
   when
      IsValid()
      OwnsSomething()
   then myResults.add(new Message("You are eligible"))
end