Termination w.r.t. Q of the following Term Rewriting System could not be shown:

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

r4(xs, ys, zs, nil) -> xs
r4(xs, nil, zs, cons2(w, ws)) -> r4(xs, xs, cons2(succ1(zero), zs), ws)
r4(xs, cons2(y, ys), nil, cons2(w, ws)) -> r4(xs, xs, cons2(succ1(zero), nil), ws)
r4(xs, cons2(y, ys), cons2(z, zs), cons2(w, ws)) -> r4(ys, cons2(y, ys), zs, cons2(succ1(zero), cons2(w, ws)))

Q is empty.


QTRS
  ↳ DependencyPairsProof

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

r4(xs, ys, zs, nil) -> xs
r4(xs, nil, zs, cons2(w, ws)) -> r4(xs, xs, cons2(succ1(zero), zs), ws)
r4(xs, cons2(y, ys), nil, cons2(w, ws)) -> r4(xs, xs, cons2(succ1(zero), nil), ws)
r4(xs, cons2(y, ys), cons2(z, zs), cons2(w, ws)) -> r4(ys, cons2(y, ys), zs, cons2(succ1(zero), cons2(w, ws)))

Q is empty.

Using Dependency Pairs [1,13] we result in the following initial DP problem:
Q DP problem:
The TRS P consists of the following rules:

R4(xs, cons2(y, ys), nil, cons2(w, ws)) -> R4(xs, xs, cons2(succ1(zero), nil), ws)
R4(xs, cons2(y, ys), cons2(z, zs), cons2(w, ws)) -> R4(ys, cons2(y, ys), zs, cons2(succ1(zero), cons2(w, ws)))
R4(xs, nil, zs, cons2(w, ws)) -> R4(xs, xs, cons2(succ1(zero), zs), ws)

The TRS R consists of the following rules:

r4(xs, ys, zs, nil) -> xs
r4(xs, nil, zs, cons2(w, ws)) -> r4(xs, xs, cons2(succ1(zero), zs), ws)
r4(xs, cons2(y, ys), nil, cons2(w, ws)) -> r4(xs, xs, cons2(succ1(zero), nil), ws)
r4(xs, cons2(y, ys), cons2(z, zs), cons2(w, ws)) -> r4(ys, cons2(y, ys), zs, cons2(succ1(zero), cons2(w, ws)))

Q is empty.
We have to consider all minimal (P,Q,R)-chains.

↳ QTRS
  ↳ DependencyPairsProof
QDP

Q DP problem:
The TRS P consists of the following rules:

R4(xs, cons2(y, ys), nil, cons2(w, ws)) -> R4(xs, xs, cons2(succ1(zero), nil), ws)
R4(xs, cons2(y, ys), cons2(z, zs), cons2(w, ws)) -> R4(ys, cons2(y, ys), zs, cons2(succ1(zero), cons2(w, ws)))
R4(xs, nil, zs, cons2(w, ws)) -> R4(xs, xs, cons2(succ1(zero), zs), ws)

The TRS R consists of the following rules:

r4(xs, ys, zs, nil) -> xs
r4(xs, nil, zs, cons2(w, ws)) -> r4(xs, xs, cons2(succ1(zero), zs), ws)
r4(xs, cons2(y, ys), nil, cons2(w, ws)) -> r4(xs, xs, cons2(succ1(zero), nil), ws)
r4(xs, cons2(y, ys), cons2(z, zs), cons2(w, ws)) -> r4(ys, cons2(y, ys), zs, cons2(succ1(zero), cons2(w, ws)))

Q is empty.
We have to consider all minimal (P,Q,R)-chains.