MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          fib(x) -> fibiter(x,0(),0(),s(0()))
          fibiter(b,c,x,y) -> if(lt(c,b),b,c,x,y)
          if(false(),b,c,x,y) -> x
          if(true(),b,c,x,y) -> fibiter(b,s(c),y,plus(x,y))
          lt(x,0()) -> false()
          lt(0(),s(y)) -> true()
          lt(s(x),s(y)) -> lt(x,y)
          plus(0(),y) -> y
          plus(s(x),y) -> s(plus(x,y))
      - Signature:
          {fib/1,fibiter/4,if/5,lt/2,plus/2} / {0/0,false/0,s/1,true/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {fib,fibiter,if,lt,plus} and constructors {0,false,s,true}
  + Applied Processor:
      EmptyProcessor
  + Details:
      The problem is still open.
MAYBE