YES(?,O(n^1))
* Step 1: ArgumentFilter WORST_CASE(?,O(n^1))
    + 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:
        ArgumentFilter [2]
    + Details:
        We remove following argument positions: [2].
* Step 2: FromIts WORST_CASE(?,O(n^1))
    + Considered Problem:
        Rules:
          0. f2(A,B)   -> f2(-1 + A,B)   [-21 + B >= 0 && A >= 31] (?,1)
          1. f2(A,B)   -> f300(A,-1 + B) [-21 + B >= 0 && 30 >= A] (?,1)
          2. f300(A,B) -> f2(A,B)        [B >= 21]                 (?,1)
          3. f300(A,B) -> f1(A,B)        [20 >= B]                 (?,1)
          4. f3(A,B)   -> f300(A,B)      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:
        FromIts
    + Details:
        ()
* Step 3: AddSinks WORST_CASE(?,O(n^1))
    + Considered Problem:
        Rules:
          f2(A,B)   -> f2(-1 + A,B)    [-21 + B >= 0 && A >= 31]
          f2(A,B)   -> f300(A,-1 + B)  [-21 + B >= 0 && 30 >= A]
          f300(A,B) -> f2(A,B)         [B >= 21]
          f300(A,B) -> f1(A,B)         [20 >= B]
          f3(A,B)   -> f300(A,B)       True
        Signature:
          {(f1,3);(f2,3);(f3,3);(f300,3)}
        Rule Graph:
          [0->{0,1},1->{2,3},2->{0,1},3->{},4->{2,3}]
    + Applied Processor:
        AddSinks
    + Details:
        ()
* Step 4: Decompose WORST_CASE(?,O(n^1))
    + Considered Problem:
        Rules:
          f2(A,B)   -> f2(-1 + A,B)    [-21 + B >= 0 && A >= 31]
          f2(A,B)   -> f300(A,-1 + B)  [-21 + B >= 0 && 30 >= A]
          f300(A,B) -> f2(A,B)         [B >= 21]
          f300(A,B) -> f1(A,B)         [20 >= B]
          f3(A,B)   -> f300(A,B)       True
          f1(A,B)   -> exitus616(A,B)  True
        Signature:
          {(exitus616,2);(f1,3);(f2,3);(f3,3);(f300,3)}
        Rule Graph:
          [0->{0,1},1->{2,3},2->{0,1},3->{5},4->{2,3}]
    + Applied Processor:
        Decompose Greedy
    + Details:
        We construct a looptree:
          P: [0,1,2,3,4,5]
          |
          `- p:[0,2,1] c: [0,1,2]
* Step 5: AbstractSize WORST_CASE(?,O(n^1))
    + Considered Problem:
        (Rules:
          f2(A,B)   -> f2(-1 + A,B)    [-21 + B >= 0 && A >= 31]
          f2(A,B)   -> f300(A,-1 + B)  [-21 + B >= 0 && 30 >= A]
          f300(A,B) -> f2(A,B)         [B >= 21]
          f300(A,B) -> f1(A,B)         [20 >= B]
          f3(A,B)   -> f300(A,B)       True
          f1(A,B)   -> exitus616(A,B)  True
        Signature:
          {(exitus616,2);(f1,3);(f2,3);(f3,3);(f300,3)}
        Rule Graph:
          [0->{0,1},1->{2,3},2->{0,1},3->{5},4->{2,3}]
        ,We construct a looptree:
          P: [0,1,2,3,4,5]
          |
          `- p:[0,2,1] c: [0,1,2])
    + Applied Processor:
        AbstractSize Minimize
    + Details:
        ()
* Step 6: AbstractFlow WORST_CASE(?,O(n^1))
    + Considered Problem:
        Program:
          Domain: [A,B,0.0]
           f2    ~>  f2          [A <= A, B <= B]
           f2    ~>  f300        [A <= A, B <= B]
           f300  ~>  f2          [A <= A, B <= B]
           f300  ~>  f1          [A <= A, B <= B]
           f3    ~>  f300        [A <= A, B <= B]
           f1    ~>  exitus616   [A <= A, B <= B]
          + Loop: [0.0 <= 21*K + A + B]
               f2    ~>  f2     [A <= A, B <= B]
               f300  ~>  f2     [A <= A, B <= B]
               f2    ~>  f300   [A <= A, B <= B]
    + Applied Processor:
        AbstractFlow
    + Details:
        ()
* Step 7: Lare WORST_CASE(?,O(n^1))
    + Considered Problem:
        Program:
          Domain: [tick,huge,K,A,B,0.0]
           f2    ~>  f2          []
           f2    ~>  f300        []
           f300  ~>  f2          []
           f300  ~>  f1          []
           f3    ~>  f300        []
           f1    ~>  exitus616   []
          + Loop: [A ~+> 0.0,B ~+> 0.0,K ~*> 0.0]
               f2    ~>  f2     []
               f300  ~>  f2     []
               f2    ~>  f300   []
    + Applied Processor:
        Lare
    + Details:
         f3  ~>  exitus616   [A ~+> 0.0,A ~+> tick,B ~+> 0.0,B ~+> tick,tick ~+> tick,K ~*> 0.0,K ~*> tick]
        + <f300  ~>  f300>  [A ~+> 0.0,A ~+> tick,B ~+> 0.0,B ~+> tick,tick ~+> tick,K ~*> 0.0,K ~*> tick]

YES(?,O(n^1))