ceta_equiv: 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 to remove from the DP problem
  pairs:
  
  active#(app(nil, YS)) -> mark#(YS)
  active#(app(cons(X, XS), YS)) -> mark#(cons(X, app(XS, YS)))
  active#(from(X)) -> mark#(cons(X, from(s(X))))
  active#(zWadr(cons(X, XS), cons(Y, YS))) -> mark#(cons(app(Y, cons(X, nil)), zWadr(XS, YS)))
  active#(prefix(L)) -> mark#(cons(nil, zWadr(L, prefix(L))))
  mark#(app(X1, X2)) -> active#(app(mark(X1), mark(X2)))
  mark#(app(X1, X2)) -> mark#(X1)
  mark#(app(X1, X2)) -> mark#(X2)
  mark#(cons(X1, X2)) -> active#(cons(mark(X1), X2))
  mark#(cons(X1, X2)) -> mark#(X1)
  mark#(from(X)) -> active#(from(mark(X)))
  mark#(from(X)) -> mark#(X)
  mark#(s(X)) -> active#(s(mark(X)))
  mark#(s(X)) -> mark#(X)
  mark#(zWadr(X1, X2)) -> active#(zWadr(mark(X1), mark(X2)))
  mark#(zWadr(X1, X2)) -> mark#(X1)
  mark#(zWadr(X1, X2)) -> mark#(X2)
  mark#(prefix(X)) -> active#(prefix(mark(X)))
  mark#(prefix(X)) -> mark#(X)
  rules:
  
  active(app(nil, YS)) -> mark(YS)
  active(app(cons(X, XS), YS)) -> mark(cons(X, app(XS, YS)))
  active(from(X)) -> mark(cons(X, from(s(X))))
  active(zWadr(nil, YS)) -> mark(nil)
  active(zWadr(XS, nil)) -> mark(nil)
  active(zWadr(cons(X, XS), cons(Y, YS))) -> mark(cons(app(Y, cons(X, nil)), zWadr(XS, YS)))
  active(prefix(L)) -> mark(cons(nil, zWadr(L, prefix(L))))
  app(mark(X1), X2) -> app(X1, X2)
  app(X1, mark(X2)) -> app(X1, X2)
  app(active(X1), X2) -> app(X1, X2)
  app(X1, active(X2)) -> app(X1, X2)
  cons(mark(X1), X2) -> cons(X1, X2)
  cons(X1, mark(X2)) -> cons(X1, X2)
  cons(active(X1), X2) -> cons(X1, X2)
  cons(X1, active(X2)) -> cons(X1, X2)
  from(mark(X)) -> from(X)
  from(active(X)) -> from(X)
  mark(app(X1, X2)) -> active(app(mark(X1), mark(X2)))
  mark(nil) -> active(nil)
  mark(cons(X1, X2)) -> active(cons(mark(X1), X2))
  mark(from(X)) -> active(from(mark(X)))
  mark(s(X)) -> active(s(mark(X)))
  mark(zWadr(X1, X2)) -> active(zWadr(mark(X1), mark(X2)))
  mark(prefix(X)) -> active(prefix(mark(X)))
  prefix(mark(X)) -> prefix(X)
  prefix(active(X)) -> prefix(X)
  s(mark(X)) -> s(X)
  s(active(X)) -> s(X)
  zWadr(mark(X1), X2) -> zWadr(X1, X2)
  zWadr(X1, mark(X2)) -> zWadr(X1, X2)
  zWadr(active(X1), X2) -> zWadr(X1, X2)
  zWadr(X1, active(X2)) -> zWadr(X1, X2)
  
   the pairs 
  active#(app(nil, YS)) -> mark#(YS)
  active#(app(cons(X, XS), YS)) -> mark#(cons(X, app(XS, YS)))
  active#(from(X)) -> mark#(cons(X, from(s(X))))
  active#(zWadr(cons(X, XS), cons(Y, YS))) -> mark#(cons(app(Y, cons(X, nil)), zWadr(XS, YS)))
  active#(prefix(L)) -> mark#(cons(nil, zWadr(L, prefix(L))))
  mark#(app(X1, X2)) -> active#(app(mark(X1), mark(X2)))
  mark#(app(X1, X2)) -> mark#(X1)
  mark#(app(X1, X2)) -> mark#(X2)
  mark#(cons(X1, X2)) -> active#(cons(mark(X1), X2))
  mark#(from(X)) -> active#(from(mark(X)))
  mark#(from(X)) -> mark#(X)
  mark#(s(X)) -> active#(s(mark(X)))
  mark#(zWadr(X1, X2)) -> active#(zWadr(mark(X1), mark(X2)))
  mark#(zWadr(X1, X2)) -> mark#(X1)
  mark#(zWadr(X1, X2)) -> mark#(X2)
  mark#(prefix(X)) -> active#(prefix(mark(X)))
  mark#(prefix(X)) -> mark#(X)
  
  could not apply the generic root reduction pair processor with the following
  SCNP-version with mu = MAX and the level mapping defined by 
  pi(mark#) = [(epsilon,0)]
  pi(active#) = [(1,3)]
  Argument Filter: 
  pi(mark#/1) = [1]
  pi(app/2) = [1,2]
  pi(active#/1) = []
  pi(mark/1) = 1
  pi(nil/0) = []
  pi(cons/2) = 1
  pi(from/1) = [1]
  pi(s/1) = 1
  pi(zWadr/2) = [1,2]
  pi(prefix/1) = [1]
  pi(active/1) = 1
  
  RPO with the following precedence
  precedence(mark#[1]) = 0
  precedence(app[2]) = 1
  precedence(active#[1]) = 3
  precedence(nil[0]) = 0
  precedence(from[1]) = 0
  precedence(zWadr[2]) = 2
  precedence(prefix[1]) = 0
  
  precedence(_) = 0
  and the following status
  status(mark#[1]) = mul
  status(app[2]) = mul
  status(active#[1]) = mul
  status(nil[0]) = mul
  status(from[1]) = mul
  status(zWadr[2]) = mul
  status(prefix[1]) = mul
  
  status(_) = lex
  
  problem when orienting DPs
  cannot orient pair active#(prefix(L)) -> mark#(cons(nil, zWadr(L, prefix(L)))) strictly:
  [(prefix(L),3)] >mu [(mark#(cons(nil, zWadr(L, prefix(L)))),0)] could not be ensured