ceta_eq: termination proof not accepted
1: error below switch to dependency pairs
1.1: error below the dependency graph processor
 1.1.4: error when applying the reduction pair processor with usable rules to remove from the DP problem
  pairs:
  
  __#(mark(X1), X2) -> __#(X1, X2)
  __#(X1, mark(X2)) -> __#(X1, X2)
  __#(ok(X1), ok(X2)) -> __#(X1, X2)
  rules:
  
  __(mark(X1), X2) -> mark(__(X1, X2))
  __(X1, mark(X2)) -> mark(__(X1, X2))
  __(ok(X1), ok(X2)) -> ok(__(X1, X2))
  active(__(__(X, Y), Z)) -> mark(__(X, __(Y, Z)))
  active(__(X, nil)) -> mark(X)
  active(__(nil, X)) -> mark(X)
  active(and(tt, X)) -> mark(X)
  active(isNePal(__(I, __(P, I)))) -> mark(tt)
  active(__(X1, X2)) -> __(active(X1), X2)
  active(__(X1, X2)) -> __(X1, active(X2))
  active(and(X1, X2)) -> and(active(X1), X2)
  active(isNePal(X)) -> isNePal(active(X))
  and(mark(X1), X2) -> mark(and(X1, X2))
  and(ok(X1), ok(X2)) -> ok(and(X1, X2))
  isNePal(mark(X)) -> mark(isNePal(X))
  isNePal(ok(X)) -> ok(isNePal(X))
  proper(__(X1, X2)) -> __(proper(X1), proper(X2))
  proper(nil) -> ok(nil)
  proper(and(X1, X2)) -> and(proper(X1), proper(X2))
  proper(tt) -> ok(tt)
  proper(isNePal(X)) -> isNePal(proper(X))
  top(mark(X)) -> top(proper(X))
  top(ok(X)) -> top(active(X))
  
   the pairs 
  __#(mark(X1), X2) -> __#(X1, X2)
  __#(X1, mark(X2)) -> __#(X1, 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(__#) = [(1,0),(2,2)]
  Argument Filter: 
  pi(__#/2) = []
  pi(mark/1) = [1]
  pi(ok/1) = 1
  
  RPO with the following precedence
  precedence(__#[2]) = 0
  precedence(mark[1]) = 1
  
  precedence(_) = 0
  and the following status
  status(__#[2]) = lex
  status(mark[1]) = lex
  
  status(_) = lex
  
  problem when orienting DPs
  cannot orient pair __#(ok(X1), ok(X2)) -> __#(X1, X2) weakly:
  [(ok(X1),0),(ok(X2),2)] >=mu [(X1,0),(X2,2)] could not be ensured