ceta_eq: termination proof not accepted
1: error below switch to dependency pairs
1.1: error below the dependency graph processor
 1.1.2: error when applying the reduction pair processor with usable rules to remove from the DP problem
  pairs:
  
  active#(f(f(a))) -> mark#(f(g(f(a))))
  mark#(f(X)) -> active#(f(X))
  rules:
  
  active(f(f(a))) -> mark(f(g(f(a))))
  f(mark(X)) -> f(X)
  f(active(X)) -> f(X)
  g(mark(X)) -> g(X)
  g(active(X)) -> g(X)
  mark(f(X)) -> active(f(X))
  mark(a) -> active(a)
  mark(g(X)) -> active(g(mark(X)))
  
   the pairs 
  mark#(f(X)) -> active#(f(X))
  
  could not apply the generic root reduction pair processor with the following
  SCNP-version with mu = MS and the level mapping defined by 
  pi(mark#) = [(epsilon,0),(1,0)]
  pi(active#) = [(epsilon,0),(1,0)]
  Argument Filter: 
  pi(mark#/1) = []
  pi(f/1) = 1
  pi(active#/1) = []
  pi(a/0) = []
  pi(g/1) = []
  pi(active/1) = 1
  pi(mark/1) = 1
  
  RPO with the following precedence
  precedence(mark#[1]) = 1
  precedence(active#[1]) = 0
  precedence(a[0]) = 1
  precedence(g[1]) = 0
  
  precedence(_) = 0
  and the following status
  status(mark#[1]) = lex
  status(active#[1]) = lex
  status(a[0]) = lex
  status(g[1]) = lex
  
  status(_) = lex
  
  problem when orienting DPs
  cannot orient pair active#(f(f(a))) -> mark#(f(g(f(a)))) weakly:
  [(active#(f(f(a))),0),(f(f(a)),0)] >=mu [(mark#(f(g(f(a)))),0),(f(g(f(a))),0)] could not be ensured