ceta_eq: termination proof not accepted
1: error below switch to dependency pairs
1.1: error below the dependency graph processor
 1.1.1: error when applying the reduction pair processor with usable rules to remove from the DP problem
  pairs:
  
  app#(app(flatwith, f), app(leaf, x)) -> app#(f, x)
  app#(app(flatwith, f), app(node, xs)) -> app#(app(flatwithsub, f), xs)
  app#(app(flatwithsub, f), app(app(cons, x), xs)) -> app#(app(flatwith, f), x)
  app#(app(flatwithsub, f), app(app(cons, x), xs)) -> app#(app(flatwithsub, f), xs)
  rules:
  
  app(app(append, nil), ys) -> ys
  app(app(append, app(app(cons, x), xs)), ys) -> app(app(cons, x), app(app(append, xs), ys))
  app(app(flatwith, f), app(leaf, x)) -> app(app(cons, app(f, x)), nil)
  app(app(flatwith, f), app(node, xs)) -> app(app(flatwithsub, f), xs)
  app(app(flatwithsub, f), nil) -> nil
  app(app(flatwithsub, f), app(app(cons, x), xs)) -> app(app(append, app(app(flatwith, f), x)), app(app(flatwithsub, f), xs))
  
   the pairs 
  app#(app(flatwith, f), app(leaf, x)) -> app#(f, x)
  
  could not apply the generic root reduction pair processor with the following
  SCNP-version with mu = MAX and the level mapping defined by 
  pi(app#) = [(1,1)]
  Argument Filter: 
  pi(app/2) = [1,2]
  pi(flatwith/0) = []
  pi(node/0) = []
  pi(flatwithsub/0) = []
  pi(cons/0) = []
  pi(leaf/0) = []
  
  RPO with the following precedence
  precedence(app[2]) = 0
  precedence(flatwith[0]) = 1
  precedence(node[0]) = 0
  precedence(flatwithsub[0]) = 1
  precedence(cons[0]) = 1
  precedence(leaf[0]) = 2
  
  precedence(_) = 0
  and the following status
  status(app[2]) = mul
  status(flatwith[0]) = mul
  status(node[0]) = mul
  status(flatwithsub[0]) = mul
  status(cons[0]) = mul
  status(leaf[0]) = mul
  
  status(_) = lex
  
  problem when orienting DPs
  cannot orient pair app#(app(flatwith, f), app(node, xs)) -> app#(app(flatwithsub, f), xs) weakly:
  [(app(flatwith, f),1)] >=mu [(app(flatwithsub, f),1)] could not be ensured