YES
* Step 1: TrivialSCCs YES
    + Considered Problem:
        Rules:
          0. l0(A,B) -> l1(A,B)          True                  (1,1)
          1. l1(A,B) -> l1(-1 + A,A + B) [A >= 1]              (?,1)
          2. l1(A,B) -> l2(A,B)          [0 >= A]              (?,1)
          3. l2(A,B) -> l2(A,-1 + B)     [-1*A >= 0 && B >= 1] (?,1)
        Signature:
          {(l0,2);(l1,2);(l2,2)}
        Flow Graph:
          [0->{1,2},1->{1,2},2->{3},3->{3}]
        
    + Applied Processor:
        TrivialSCCs
    + Details:
        All trivial SCCs of the transition graph admit timebound 1.
* Step 2: Looptree YES
    + Considered Problem:
        Rules:
          0. l0(A,B) -> l1(A,B)          True                  (1,1)
          1. l1(A,B) -> l1(-1 + A,A + B) [A >= 1]              (?,1)
          2. l1(A,B) -> l2(A,B)          [0 >= A]              (1,1)
          3. l2(A,B) -> l2(A,-1 + B)     [-1*A >= 0 && B >= 1] (?,1)
        Signature:
          {(l0,2);(l1,2);(l2,2)}
        Flow Graph:
          [0->{1,2},1->{1,2},2->{3},3->{3}]
        
    + Applied Processor:
        Looptree
    + Details:
        We construct a looptree:
          P: [0,1,2,3]
          |
          +- p:[1] c: [1]
          |
          `- p:[3] c: [3]

YES