MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          empty(cons(n,x)) -> false()
          empty(nil()) -> true()
          head(cons(n,x)) -> n
          if(false(),b,x) -> if2(b,x)
          if(true(),b,x) -> weight_undefined_error()
          if2(false(),x) -> weight(sum(x,cons(0(),tail(tail(x)))))
          if2(true(),x) -> head(x)
          sum(cons(0(),x),y) -> sum(x,y)
          sum(cons(s(n),x),cons(m,y)) -> sum(cons(n,x),cons(s(m),y))
          sum(nil(),y) -> y
          tail(cons(n,x)) -> x
          tail(nil()) -> nil()
          weight(x) -> if(empty(x),empty(tail(x)),x)
      - Signature:
          {empty/1,head/1,if/3,if2/2,sum/2,tail/1,weight/1} / {0/0,cons/2,false/0,nil/0,s/1,true/0
          ,weight_undefined_error/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {empty,head,if,if2,sum,tail,weight} and constructors {0
          ,cons,false,nil,s,true,weight_undefined_error}
  + Applied Processor:
      Ara {heuristics_ = NoHeuristics, minDegree = 1, maxDegree = 3, araTimeout = 60, araFindStrictRules = Nothing, araSmtSolver = Z3}
  + Details:
      The input can not be schown compatible.
MAYBE