NO

Prover = TRS(tech=PATTERN_RULES, nb_unfoldings=unlimited, max_nb_unfolded_rules=200)

** BEGIN proof argument **
The following pattern rule was generated by the strategy
presented in Sect. 3 of [Emmes, Enger, Giesl, IJCAR'12]:
[iteration = 2] f(tt,Cons(tt,_0)){_0->Cons(tt,_0)}^n{_0->nil} -> f(tt,Cons(tt,Cons(tt,_0))){_0->Cons(tt,_0)}^n{_0->nil}
We apply Theorem 8 of [Emmes, Enger, Giesl, IJCAR'12]
on this rule with m = 1, b = 1, pi = epsilon,
sigma' = {} and mu' = {}.
Hence the term f(tt,Cons(tt,nil)), obtained from
instantiating n with 0 in the left-hand side of
the rule, starts an infinite derivation w.r.t.
the analyzed TRS.
** END proof argument **

** BEGIN proof description **
## Searching for a generalized rewrite rule
(a rule whose right-hand side contains a variable
that does not occur in the left-hand side)...
No generalized rewrite rule found!

## Applying the DP framework...
## Round 1:
  ## DP problem: 
  Dependency pairs = [f^#(tt,_0) -> f^#(isList(_0),Cons(tt,_0))]
  TRS = {f(tt,_0) -> f(isList(_0),Cons(tt,_0)), isList(Cons(tt,_0)) -> isList(_0), isList(nil) -> tt}
    ## Trying with homeomorphic embeddings... Failed!
    ## Trying with polynomial interpretations... Too many coefficients (13)! Aborting!
    ## Trying with lexicographic path orders... Failed!
    ## Trying to prove nontermination by unfolding the dependency pairs with the rules of the TRS
        # Iteration 0: nontermination not detected, 1 unfolded rule generated.
        # Iteration 1: nontermination not detected, 5 unfolded rules generated.
        # Iteration 2: nontermination detected, 14 unfolded rules generated.
        Here is the successful unfolding. Let IR be the TRS under analysis.
        IR contains the dependency pair f^#(tt,_0) -> f^#(isList(_0),Cons(tt,_0)).
        We apply (I) of [Emmes, Enger, Giesl, IJCAR'12] to this dependency pair.
        ==> P0 = f^#(tt,_0){}^n{} -> f^#(isList(_0),Cons(tt,_0)){}^n{} is in U_IR^0.
        We apply (VI) of [Emmes, Enger, Giesl, IJCAR'12] to this pattern rule
        at position [0] using the pattern rule
        isList(Cons(tt,_0)){_0->Cons(tt,_0)}^n{_0->_1} -> isList(_1){_0->Cons(tt,_0)}^n{_0->_1}
        obtained from IR.
        ==> P1 = f^#(tt,Cons(tt,_0)){_0->Cons(tt,_0)}^n{_0->_1} -> f^#(isList(_1),Cons(tt,Cons(tt,_0))){_0->Cons(tt,_0)}^n{_0->_1} is in U_IR^1.
        We apply (V) + (IX) of [Emmes, Enger, Giesl, IJCAR'12] to this pattern rule
        at position [0] using the rule
        isList(nil) -> tt
        of IR.
        ==> P2 = f^#(tt,Cons(tt,_0)){_0->Cons(tt,_0)}^n{_0->nil} -> f^#(tt,Cons(tt,Cons(tt,_0))){_0->Cons(tt,_0)}^n{_0->nil} is in U_IR^2.
  This DP problem is infinite.

** END proof description **

Proof stopped at iteration 2
Number of unfolded rules generated by this proof = 20
Number of unfolded rules generated by all the parallel proofs = 61