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