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:

and(tt) → X
length(cons(N)) → s(length(L))
zeroscons(0)
length(nil) → 0



GTRS
  ↳ CritRuleProof

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

and(tt) → X
length(cons(N)) → s(length(L))
zeroscons(0)
length(nil) → 0


The rule and(tt) → X contains free variables in its right-hand side. Hence the TRS is not-terminating.