YES
* Step 1: TrivialSCCs YES
    + Considered Problem:
        Rules:
          0. f4(A,B,C,D,E,F,G) -> f4(A + B,B,C,D,E,F,G) [-1 + -1*B >= 0 && A >= 0]     (?,1)
          1. f4(A,B,C,D,E,F,G) -> f6(A,B,0,0,0,0,0)     [-1 + -1*B >= 0 && 0 >= 1 + A] (?,1)
          2. f5(A,B,C,D,E,F,G) -> f4(A,B,C,D,E,F,G)     [0 >= 1 + B]                   (1,1)
          3. f5(A,B,C,D,E,F,G) -> f6(A,B,0,0,0,0,0)     [B >= 0]                       (1,1)
        Signature:
          {(f4,7);(f5,7);(f6,7)}
        Flow Graph:
          [0->{0,1},1->{},2->{0,1},3->{}]
        
    + Applied Processor:
        TrivialSCCs
    + Details:
        All trivial SCCs of the transition graph admit timebound 1.
* Step 2: Looptree YES
    + Considered Problem:
        Rules:
          0. f4(A,B,C,D,E,F,G) -> f4(A + B,B,C,D,E,F,G) [-1 + -1*B >= 0 && A >= 0]     (?,1)
          1. f4(A,B,C,D,E,F,G) -> f6(A,B,0,0,0,0,0)     [-1 + -1*B >= 0 && 0 >= 1 + A] (1,1)
          2. f5(A,B,C,D,E,F,G) -> f4(A,B,C,D,E,F,G)     [0 >= 1 + B]                   (1,1)
          3. f5(A,B,C,D,E,F,G) -> f6(A,B,0,0,0,0,0)     [B >= 0]                       (1,1)
        Signature:
          {(f4,7);(f5,7);(f6,7)}
        Flow Graph:
          [0->{0,1},1->{},2->{0,1},3->{}]
        
    + Applied Processor:
        Looptree
    + Details:
        We construct a looptree:
          P: [0,1,2,3]
          |
          `- p:[0] c: [0]

YES