Termination of the given GTRS could be disproven:

(0) Obligation:

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

2nd(cons(X)) → Y
from(X) → cons(X)

(1) CritRuleProof (EQUIVALENT transformation)

The rule 2nd(cons(X)) → Y contains free variables in its right-hand side. Hence the TRS is not-terminating.

(2) FALSE