MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          active(f(x)) -> f(active(x))
          active(f(x)) -> mark(x)
          check(x) -> start(match(f(X()),x))
          check(f(x)) -> f(check(x))
          f(found(x)) -> found(f(x))
          f(mark(x)) -> mark(f(x))
          f(ok(x)) -> ok(f(x))
          match(X(),x) -> proper(x)
          match(f(x),f(y)) -> f(match(x,y))
          proper(c()) -> ok(c())
          proper(f(x)) -> f(proper(x))
          start(ok(x)) -> found(x)
          top(active(c())) -> top(mark(c()))
          top(found(x)) -> top(active(x))
          top(mark(x)) -> top(check(x))
      - Signature:
          {active/1,check/1,f/1,match/2,proper/1,start/1,top/1} / {X/0,c/0,found/1,mark/1,ok/1}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {active,check,f,match,proper,start
          ,top} and constructors {X,c,found,mark,ok}
  + Applied Processor:
      NaturalPI {shape = Mixed 3, restrict = NoRestrict, uargs = UArgs, urules = URules, selector = Nothing}
  + Details:
      Incompatible
MAYBE