Termination of the following Term Rewriting System could be disproven:

Generalized rewrite system (where rules with free variables on rhs are allowed):
The TRS R consists of the following rules:

U12(tt) → s(length(L))
zeroscons(0)
U11(tt) → U12(tt)
length(nil) → 0
length(cons(N)) → U11(tt)



GTRS
  ↳ CritRuleProof

Generalized rewrite system (where rules with free variables on rhs are allowed):
The TRS R consists of the following rules:

U12(tt) → s(length(L))
zeroscons(0)
U11(tt) → U12(tt)
length(nil) → 0
length(cons(N)) → U11(tt)


The rule U12(tt) → s(length(L)) contains free variables in its right-hand side. Hence the TRS is not-terminating.