YES(?,POLY)
* Step 1: TrivialSCCs WORST_CASE(?,POLY)
    + Considered Problem:
        Rules:
          0. f2(A,B,C)   -> f2(-1 + A,B,C)   [-21 + B >= 0 && A >= 31] (?,1)
          1. f2(A,B,C)   -> f300(A,-1 + B,C) [-21 + B >= 0 && 30 >= A] (?,1)
          2. f300(A,B,C) -> f2(A,B,C)        [B >= 21]                 (?,1)
          3. f300(A,B,C) -> f1(A,B,D)        [20 >= B]                 (?,1)
          4. f3(A,B,C)   -> f300(A,B,C)      True                      (1,1)
        Signature:
          {(f1,3);(f2,3);(f3,3);(f300,3)}
        Flow Graph:
          [0->{0,1},1->{2,3},2->{0,1},3->{},4->{2,3}]
        
    + Applied Processor:
        TrivialSCCs
    + Details:
        All trivial SCCs of the transition graph admit timebound 1.
* Step 2: AddSinks WORST_CASE(?,POLY)
    + Considered Problem:
        Rules:
          0. f2(A,B,C)   -> f2(-1 + A,B,C)   [-21 + B >= 0 && A >= 31] (?,1)
          1. f2(A,B,C)   -> f300(A,-1 + B,C) [-21 + B >= 0 && 30 >= A] (?,1)
          2. f300(A,B,C) -> f2(A,B,C)        [B >= 21]                 (?,1)
          3. f300(A,B,C) -> f1(A,B,D)        [20 >= B]                 (1,1)
          4. f3(A,B,C)   -> f300(A,B,C)      True                      (1,1)
        Signature:
          {(f1,3);(f2,3);(f3,3);(f300,3)}
        Flow Graph:
          [0->{0,1},1->{2,3},2->{0,1},3->{},4->{2,3}]
        
    + Applied Processor:
        AddSinks
    + Details:
        ()
* Step 3: LooptreeTransformer WORST_CASE(?,POLY)
    + Considered Problem:
        Rules:
          0. f2(A,B,C)   -> f2(-1 + A,B,C)   [-21 + B >= 0 && A >= 31] (?,1)
          1. f2(A,B,C)   -> f300(A,-1 + B,C) [-21 + B >= 0 && 30 >= A] (?,1)
          2. f300(A,B,C) -> f2(A,B,C)        [B >= 21]                 (?,1)
          3. f300(A,B,C) -> f1(A,B,D)        [20 >= B]                 (?,1)
          4. f3(A,B,C)   -> f300(A,B,C)      True                      (1,1)
          5. f300(A,B,C) -> exitus616(A,B,C) True                      (?,1)
        Signature:
          {(exitus616,3);(f1,3);(f2,3);(f3,3);(f300,3)}
        Flow Graph:
          [0->{0,1},1->{2,3,5},2->{0,1},3->{},4->{2,3,5},5->{}]
        
    + Applied Processor:
        LooptreeTransformer
    + Details:
        We construct a looptree:
          P: [0,1,2,3,4,5]
          |
          `- p:[0,2,1] c: [2]
             |
             `- p:[0] c: [0]
* Step 4: SizeAbstraction WORST_CASE(?,POLY)
    + Considered Problem:
        (Rules:
          0. f2(A,B,C)   -> f2(-1 + A,B,C)   [-21 + B >= 0 && A >= 31] (?,1)
          1. f2(A,B,C)   -> f300(A,-1 + B,C) [-21 + B >= 0 && 30 >= A] (?,1)
          2. f300(A,B,C) -> f2(A,B,C)        [B >= 21]                 (?,1)
          3. f300(A,B,C) -> f1(A,B,D)        [20 >= B]                 (?,1)
          4. f3(A,B,C)   -> f300(A,B,C)      True                      (1,1)
          5. f300(A,B,C) -> exitus616(A,B,C) True                      (?,1)
        Signature:
          {(exitus616,3);(f1,3);(f2,3);(f3,3);(f300,3)}
        Flow Graph:
          [0->{0,1},1->{2,3,5},2->{0,1},3->{},4->{2,3,5},5->{}]
        
        ,We construct a looptree:
          P: [0,1,2,3,4,5]
          |
          `- p:[0,2,1] c: [2]
             |
             `- p:[0] c: [0])
    + Applied Processor:
        SizeAbstraction UseCFG Minimize
    + Details:
        ()
* Step 5: FlowAbstraction WORST_CASE(?,POLY)
    + Considered Problem:
        Program:
          Domain: [A,B,C,0.0,0.0.0]
           f2    ~>  f2          [A <= A, B <= B, C <= C]
           f2    ~>  f300        [A <= A, B <= B, C <= C]
           f300  ~>  f2          [A <= A, B <= B, C <= C]
           f300  ~>  f1          [A <= A, B <= B, C <= unknown]
           f3    ~>  f300        [A <= A, B <= B, C <= C]
           f300  ~>  exitus616   [A <= A, B <= B, C <= C]
          + Loop: [0.0 <= 21*K + B]
               f2    ~>  f2     [A <= A, B <= B, C <= C]
               f300  ~>  f2     [A <= A, B <= B, C <= C]
               f2    ~>  f300   [A <= A, B <= B, C <= C]
            + Loop: [0.0.0 <= A]
                 f2  ~>  f2   [A <= A, B <= B, C <= C]
    + Applied Processor:
        FlowAbstraction
    + Details:
        ()
* Step 6: LareProcessor WORST_CASE(?,POLY)
    + Considered Problem:
        Program:
          Domain: [tick,huge,K,A,B,C,0.0,0.0.0]
           f2    ~>  f2          []
           f2    ~>  f300        []
           f300  ~>  f2          []
           f300  ~>  f1          [huge ~=> C]
           f3    ~>  f300        []
           f300  ~>  exitus616   []
          + Loop: [B ~+> 0.0,K ~*> 0.0]
               f2    ~>  f2     []
               f300  ~>  f2     []
               f2    ~>  f300   []
            + Loop: [A ~=> 0.0.0]
                 f2  ~>  f2   []
    + Applied Processor:
        LareProcessor
    + Details:
         f3  ~>  exitus616   [A ~=> 0.0.0
                             ,A ~+> tick
                             ,B ~+> 0.0
                             ,B ~+> tick
                             ,tick ~+> tick
                             ,A ~*> tick
                             ,B ~*> tick
                             ,K ~*> 0.0
                             ,K ~*> tick]
         f3  ~>  f1          [A ~=> 0.0.0
                             ,huge ~=> C
                             ,A ~+> tick
                             ,B ~+> 0.0
                             ,B ~+> tick
                             ,tick ~+> tick
                             ,A ~*> tick
                             ,B ~*> tick
                             ,K ~*> 0.0
                             ,K ~*> tick]
        + <f300  ~>  f300>  [A ~=> 0.0.0
                            ,A ~+> tick
                            ,B ~+> 0.0
                            ,B ~+> tick
                            ,tick ~+> tick
                            ,A ~*> tick
                            ,B ~*> tick
                            ,K ~*> 0.0
                            ,K ~*> tick]
          + <f2  ~>  f2>  [A ~=> 0.0.0,A ~+> tick,tick ~+> tick]

YES(?,POLY)