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:
  
  copy#(s(x), y, z) -> copy#(x, y, cons(f(y), z))
  rules:
  
  copy(0, y, z) -> f(z)
  copy(s(x), y, z) -> copy(x, y, cons(f(y), z))
  f(cons(nil, y)) -> y
  f(cons(f(cons(nil, y)), z)) -> copy(n, y, z)
  
   the pairs 
  copy#(s(x), y, z) -> copy#(x, y, cons(f(y), z))
  
  could not apply the generic root reduction pair processor with the following
  SCNP-version with mu = MS and the level mapping defined by 
  pi(copy#) = [(epsilon,0),(3,1)]
  polynomial interpretration over naturals with negative constants
  Pol(copy#(x_1, x_2, x_3)) = x_2 + x_1
  Pol(s(x_1)) = 1 + x_1
  Pol(cons(x_1, x_2)) = x_2
  Pol(f(x_1)) = 0
  Pol(nil) = 0
  Pol(copy(x_1, x_2, x_3)) = 1 + x_3 + x_2
  Pol(n) = 0
  problem when orienting DPs
  cannot orient pair copy#(s(x), y, z) -> copy#(x, y, cons(f(y), z)) strictly:
  [(copy#(s(x), y, z),0),(z,1)] >mu [(copy#(x, y, cons(f(y), z)),0),(cons(f(y), z),1)] could not be ensured