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),(1,2),(3,0)]
  Argument Filter: 
  pi(copy#/3) = 3
  pi(s/1) = [1]
  pi(cons/2) = 2
  pi(f/1) = []
  pi(nil/0) = []
  pi(copy/3) = 1
  pi(n/0) = []
  
  RPO with the following precedence
  precedence(s[1]) = 0
  precedence(f[1]) = 1
  precedence(nil[0]) = 1
  precedence(n[0]) = 1
  
  precedence(_) = 0
  and the following status
  status(s[1]) = lex
  status(f[1]) = lex
  status(nil[0]) = lex
  status(n[0]) = lex
  
  status(_) = lex
  
  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),(s(x),2),(z,0)] >mu [(copy#(x, y, cons(f(y), z)),0),(x,2),(cons(f(y), z),0)] could not be ensured