MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          +(x,h()) -> x
          +(+(x,y),z) -> +(x,+(y,z))
          +(h(),x) -> x
          +(s(x),s(y)) -> s(s(+(x,y)))
          a(l,x,s(y),h()) -> a(l,x,y,s(h()))
          a(l,x,s(y),s(z)) -> a(l,x,y,a(l,x,s(y),z))
          a(l,s(x),h(),z) -> a(l,x,z,z)
          a(h(),h(),h(),x) -> s(x)
          a(s(l),h(),h(),z) -> a(l,z,h(),z)
          app(l,nil()) -> l
          app(cons(x,l),k) -> cons(x,app(l,k))
          app(nil(),k) -> k
          s(h()) -> 1()
          sum(cons(x,cons(y,l))) -> sum(cons(a(x,y,h(),h()),l))
          sum(cons(x,nil())) -> cons(x,nil())
      - Signature:
          {+/2,a/4,app/2,s/1,sum/1} / {1/0,cons/2,h/0,nil/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {+,a,app,s,sum} and constructors {1,cons,h,nil}
  + Applied Processor:
      EmptyProcessor
  + Details:
      The problem is still open.
MAYBE