ceta_eq: termination proof not accepted
1: error below switch to dependency pairs
1.1: error below the dependency graph processor
 1.1.3: error below the reduction pair processor
  1.1.3.1: error when applying the reduction pair processor with usable rules to remove from the DP problem
   pairs:
   
   proper#(f(X1, X2)) -> proper#(X1)
   proper#(f(X1, X2)) -> proper#(X2)
   rules:
   
   active(f(g(X), Y)) -> mark(f(X, f(g(X), Y)))
   active(f(X1, X2)) -> f(active(X1), X2)
   active(g(X)) -> g(active(X))
   f(mark(X1), X2) -> mark(f(X1, X2))
   f(ok(X1), ok(X2)) -> ok(f(X1, X2))
   g(mark(X)) -> mark(g(X))
   g(ok(X)) -> ok(g(X))
   proper(f(X1, X2)) -> f(proper(X1), proper(X2))
   proper(g(X)) -> g(proper(X))
   top(mark(X)) -> top(proper(X))
   top(ok(X)) -> top(active(X))
   
    the pairs 
   proper#(f(X1, X2)) -> proper#(X1)
   proper#(f(X1, X2)) -> proper#(X2)
   
   could not apply the generic root reduction pair processor with the following
   SCNP-version with mu = MS and the level mapping defined by 
   pi(proper#) = [(epsilon,0),(1,0)]
   polynomial interpretration over naturals with negative constants
   Pol(proper#(x_1)) = 1
   Pol(f(x_1, x_2)) = 1 + x_2 + x_1
   problem when orienting DPs
   cannot orient pair proper#(f(X1, X2)) -> proper#(X1) strictly:
   [(proper#(f(X1, X2)),0),(f(X1, X2),0)] >mu [(proper#(X1),0),(X1,0)] could not be ensured