text: 
  
  class CrewMember_Claim extends Timeline {
    predicate Busy {}
  }
  
  
  class CrewMember {
    CrewMember_Claim m_claim;
  
    predicate Activity {bool solved;}
  
    CrewMember() {
      m_claim = new CrewMember_Claim();
    }
  }
  
  CrewMember::Activity {
    if(solved == true) {
      if(isSingleton(object)) {
        equals(object.m_claim.Busy b);
        eq(b.state, ACTIVE);
      }
    }
  }
  
  CrewMember_Claim::Busy {
    before(object.Busy busy);
    eq(busy.state, MERGED);
  }
  