MAYBE
Time: 0.003074
TRS:
 {           plus(0(), y) -> y,
             plus(s x, y) -> s plus(x, y),
               lt(x, 0()) -> false(),
             lt(0(), s y) -> true(),
             lt(s x, s y) -> lt(x, y),
      fibiter(b, c, x, y) -> if(lt(c, b), b, c, x, y),
                    fib x -> fibiter(x, 0(), 0(), s 0()),
   if(true(), b, c, x, y) -> fibiter(b, s c, y, plus(x, y)),
  if(false(), b, c, x, y) -> x}
 DP:
  DP:
   {          plus#(s x, y) -> plus#(x, y),
              lt#(s x, s y) -> lt#(x, y),
       fibiter#(b, c, x, y) -> lt#(c, b),
       fibiter#(b, c, x, y) -> if#(lt(c, b), b, c, x, y),
                     fib# x -> fibiter#(x, 0(), 0(), s 0()),
    if#(true(), b, c, x, y) -> plus#(x, y),
    if#(true(), b, c, x, y) -> fibiter#(b, s c, y, plus(x, y))}
  TRS:
  {           plus(0(), y) -> y,
              plus(s x, y) -> s plus(x, y),
                lt(x, 0()) -> false(),
              lt(0(), s y) -> true(),
              lt(s x, s y) -> lt(x, y),
       fibiter(b, c, x, y) -> if(lt(c, b), b, c, x, y),
                     fib x -> fibiter(x, 0(), 0(), s 0()),
    if(true(), b, c, x, y) -> fibiter(b, s c, y, plus(x, y)),
   if(false(), b, c, x, y) -> x}
  EDG:
   {(plus#(s x, y) -> plus#(x, y), plus#(s x, y) -> plus#(x, y))
    (if#(true(), b, c, x, y) -> plus#(x, y), plus#(s x, y) -> plus#(x, y))
    (fibiter#(b, c, x, y) -> if#(lt(c, b), b, c, x, y), if#(true(), b, c, x, y) -> fibiter#(b, s c, y, plus(x, y)))
    (fibiter#(b, c, x, y) -> if#(lt(c, b), b, c, x, y), if#(true(), b, c, x, y) -> plus#(x, y))
    (fibiter#(b, c, x, y) -> lt#(c, b), lt#(s x, s y) -> lt#(x, y))
    (if#(true(), b, c, x, y) -> fibiter#(b, s c, y, plus(x, y)), fibiter#(b, c, x, y) -> lt#(c, b))
    (if#(true(), b, c, x, y) -> fibiter#(b, s c, y, plus(x, y)), fibiter#(b, c, x, y) -> if#(lt(c, b), b, c, x, y))
    (lt#(s x, s y) -> lt#(x, y), lt#(s x, s y) -> lt#(x, y))
    (fib# x -> fibiter#(x, 0(), 0(), s 0()), fibiter#(b, c, x, y) -> lt#(c, b))
    (fib# x -> fibiter#(x, 0(), 0(), s 0()), fibiter#(b, c, x, y) -> if#(lt(c, b), b, c, x, y))}
   STATUS:
    arrows: 0.795918
    SCCS (3):
     Scc:
      {   fibiter#(b, c, x, y) -> if#(lt(c, b), b, c, x, y),
       if#(true(), b, c, x, y) -> fibiter#(b, s c, y, plus(x, y))}
     Scc:
      {plus#(s x, y) -> plus#(x, y)}
     Scc:
      {lt#(s x, s y) -> lt#(x, y)}
     
     
     SCC (2):
      Strict:
       {   fibiter#(b, c, x, y) -> if#(lt(c, b), b, c, x, y),
        if#(true(), b, c, x, y) -> fibiter#(b, s c, y, plus(x, y))}
      Weak:
      {           plus(0(), y) -> y,
                  plus(s x, y) -> s plus(x, y),
                    lt(x, 0()) -> false(),
                  lt(0(), s y) -> true(),
                  lt(s x, s y) -> lt(x, y),
           fibiter(b, c, x, y) -> if(lt(c, b), b, c, x, y),
                         fib x -> fibiter(x, 0(), 0(), s 0()),
        if(true(), b, c, x, y) -> fibiter(b, s c, y, plus(x, y)),
       if(false(), b, c, x, y) -> x}
      Open
     
     SCC (1):
      Strict:
       {plus#(s x, y) -> plus#(x, y)}
      Weak:
      {           plus(0(), y) -> y,
                  plus(s x, y) -> s plus(x, y),
                    lt(x, 0()) -> false(),
                  lt(0(), s y) -> true(),
                  lt(s x, s y) -> lt(x, y),
           fibiter(b, c, x, y) -> if(lt(c, b), b, c, x, y),
                         fib x -> fibiter(x, 0(), 0(), s 0()),
        if(true(), b, c, x, y) -> fibiter(b, s c, y, plus(x, y)),
       if(false(), b, c, x, y) -> x}
      Open
     
     SCC (1):
      Strict:
       {lt#(s x, s y) -> lt#(x, y)}
      Weak:
      {           plus(0(), y) -> y,
                  plus(s x, y) -> s plus(x, y),
                    lt(x, 0()) -> false(),
                  lt(0(), s y) -> true(),
                  lt(s x, s y) -> lt(x, y),
           fibiter(b, c, x, y) -> if(lt(c, b), b, c, x, y),
                         fib x -> fibiter(x, 0(), 0(), s 0()),
        if(true(), b, c, x, y) -> fibiter(b, s c, y, plus(x, y)),
       if(false(), b, c, x, y) -> x}
      Open