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 below the reduction pair processor
  1.1.1.1: error below the dependency graph processor
   1.1.1.1.1: error when applying the reduction pair processor to remove from the DP problem
    pairs:
    
    len#(cons(X, Z)) -> activate#(Z)
    activate#(n__len(X)) -> len#(activate(X))
    activate#(n__len(X)) -> activate#(X)
    rules:
    
    activate(n__fst(X1, X2)) -> fst(activate(X1), activate(X2))
    activate(n__from(X)) -> from(activate(X))
    activate(n__s(X)) -> s(X)
    activate(n__add(X1, X2)) -> add(activate(X1), activate(X2))
    activate(n__len(X)) -> len(activate(X))
    activate(X) -> X
    add(0, X) -> X
    add(s(X), Y) -> s(n__add(activate(X), Y))
    add(X1, X2) -> n__add(X1, X2)
    from(X) -> cons(X, n__from(n__s(X)))
    from(X) -> n__from(X)
    fst(0, Z) -> nil
    fst(s(X), cons(Y, Z)) -> cons(Y, n__fst(activate(X), activate(Z)))
    fst(X1, X2) -> n__fst(X1, X2)
    len(nil) -> 0
    len(cons(X, Z)) -> s(n__len(activate(Z)))
    len(X) -> n__len(X)
    s(X) -> n__s(X)
    
     the pairs 
    activate#(n__len(X)) -> activate#(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(len#) = [(1,0)]
    pi(activate#) = [(1,0)]
    Argument Filter: 
    pi(cons/2) = 2
    pi(n__len/1) = [1]
    pi(activate/1) = [1]
    pi(n__fst/2) = []
    pi(fst/2) = []
    pi(n__from/1) = [1]
    pi(from/1) = [1]
    pi(n__s/1) = []
    pi(s/1) = []
    pi(n__add/2) = [1,2]
    pi(add/2) = [1,2]
    pi(len/1) = [1]
    pi(0/0) = []
    pi(nil/0) = []
    
    RPO with the following precedence
    precedence(n__len[1]) = 7
    precedence(activate[1]) = 7
    precedence(n__fst[2]) = 0
    precedence(fst[2]) = 1
    precedence(n__from[1]) = 2
    precedence(from[1]) = 4
    precedence(n__s[1]) = 3
    precedence(s[1]) = 7
    precedence(n__add[2]) = 5
    precedence(add[2]) = 6
    precedence(len[1]) = 7
    precedence(0[0]) = 1
    precedence(nil[0]) = 1
    
    precedence(_) = 0
    and the following status
    status(n__len[1]) = mul
    status(activate[1]) = mul
    status(n__fst[2]) = mul
    status(fst[2]) = mul
    status(n__from[1]) = mul
    status(from[1]) = mul
    status(n__s[1]) = mul
    status(s[1]) = mul
    status(n__add[2]) = mul
    status(add[2]) = mul
    status(len[1]) = mul
    status(0[0]) = mul
    status(nil[0]) = mul
    
    status(_) = lex
    
    problem when orienting (usable) rules
    could not orient activate(n__len(X)) >= len(activate(X))
    pi( activate(n__len(X)) ) = activate(n__len(X))
    pi( len(activate(X)) ) = len(activate(X))
    could not orient activate(n__len(X)) >=RPO len(activate(X))