NO Termination w.r.t. Q proof of /home/cern_httpd/provide/research/cycsrs/examples/collection/ab-ba-shift.srs

Termination w.r.t. Q of the given QTRS could be disproven:

0 QTRS
↳1 NonTerminationProof (⇒, 80 ms)
↳2 NO

(0) Obligation:

Q restricted rewrite system:
The TRS R consists of the following rules:

B(x) → W(M(V(x)))
M(x) → x
M(V(a(x))) → V(Xa(x))
M(V(b(x))) → V(Xb(x))
Xa(a(x)) → a(Xa(x))
Xa(b(x)) → b(Xa(x))
Xb(a(x)) → a(Xb(x))
Xb(b(x)) → b(Xb(x))
Xa(E(x)) → a(E(x))
Xb(E(x)) → b(E(x))
W(V(x)) → R(L(x))
L(a(x)) → Ya(L(x))
L(b(x)) → Yb(L(x))
L(a(b(x))) → D(b(a(x)))
Ya(D(x)) → D(a(x))
Yb(D(x)) → D(b(x))
R(D(x)) → B(x)

Q is empty.

(1) NonTerminationProof (COMPLETE transformation)

We used the non-termination processor [OPPELT08] to show that the SRS problem is infinite.

Found the self-embedding DerivationStructure:
W V a b E → W V a b E

W V a b E → W V a b E
by OverlapClosure OC 2
W V a b → W V a Xb
by OverlapClosure OC 2
W V a b → W V Xb a
by OverlapClosure OC 3
W V a b → B b a
by OverlapClosure OC 3
W V a b → R D b a
by OverlapClosure OC 2
W V → R L
by original rule (OC 1)
L a b → D b a
by original rule (OC 1)
R D → B
by original rule (OC 1)
B b → W V Xb
by OverlapClosure OC 2
B → W M V
by original rule (OC 1)
M V b → V Xb
by original rule (OC 1)
Xb a → a Xb
by original rule (OC 1)
Xb E → b E
by original rule (OC 1)

(2) NO