YES
* Step 1: TrivialSCCs YES
    + Considered Problem:
        Rules:
          0. f1(A,B,C) -> f2(A,B,C)         True               (1,1)
          1. f2(A,B,C) -> f300(A,B,D)       [B >= 3 && A >= 2] (?,1)
          2. f2(A,B,C) -> f2(1 + A,1 + B,C) [2 >= B && A >= 2] (?,1)
          3. f2(A,B,C) -> f2(1 + A,1 + B,C) [1 >= A]           (?,1)
        Signature:
          {(f1,3);(f2,3);(f300,3)}
        Flow Graph:
          [0->{1,2,3},1->{},2->{1,2,3},3->{1,2,3}]
        
    + Applied Processor:
        TrivialSCCs
    + Details:
        All trivial SCCs of the transition graph admit timebound 1.
* Step 2: UnsatPaths YES
    + Considered Problem:
        Rules:
          0. f1(A,B,C) -> f2(A,B,C)         True               (1,1)
          1. f2(A,B,C) -> f300(A,B,D)       [B >= 3 && A >= 2] (1,1)
          2. f2(A,B,C) -> f2(1 + A,1 + B,C) [2 >= B && A >= 2] (?,1)
          3. f2(A,B,C) -> f2(1 + A,1 + B,C) [1 >= A]           (?,1)
        Signature:
          {(f1,3);(f2,3);(f300,3)}
        Flow Graph:
          [0->{1,2,3},1->{},2->{1,2,3},3->{1,2,3}]
        
    + Applied Processor:
        UnsatPaths
    + Details:
        We remove following edges from the transition graph: [(2,3)]
* Step 3: Looptree YES
    + Considered Problem:
        Rules:
          0. f1(A,B,C) -> f2(A,B,C)         True               (1,1)
          1. f2(A,B,C) -> f300(A,B,D)       [B >= 3 && A >= 2] (1,1)
          2. f2(A,B,C) -> f2(1 + A,1 + B,C) [2 >= B && A >= 2] (?,1)
          3. f2(A,B,C) -> f2(1 + A,1 + B,C) [1 >= A]           (?,1)
        Signature:
          {(f1,3);(f2,3);(f300,3)}
        Flow Graph:
          [0->{1,2,3},1->{},2->{1,2},3->{1,2,3}]
        
    + Applied Processor:
        Looptree
    + Details:
        We construct a looptree:
          P: [0,1,2,3]
          |
          +- p:[3] c: [3]
          |
          `- p:[2] c: [2]

YES