NO Termination proof of rt2-8.trs

(0) Obligation:

Relative term rewrite system:
The relative TRS consists of the following R rules:

f(act, y) → f(el(nact), y)
f(x, nact) → f(x, act)
actel(nact)
l(el(x)) → el(l(x))
el(r(x)) → r(el(x))

The relative TRS consists of the following S rules:

nactl(nact)
nactr(nact)

(1) RelTRSLoopFinderProof (COMPLETE transformation)

The following loop was found:

---------- Loop: ----------

el(nact) → el(r(nact)) with rule nactr(nact) at position [0] and matcher [ ]

el(r(nact)) → r(el(nact)) with rule el(r(x)) → r(el(x)) at position [] and matcher [x / nact]

Now an instance of the first term with Matcher [ ] occurs in the last term at position [0].

Context: r([])

Therefore, the relative TRS problem does not terminate.

(2) NO