YES Termination w.r.t. Q proof of Rubio_04_p266.ari

(0) Obligation:

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

f(f(X)) → f(a(b(f(X))))
f(a(g(X))) → b(X)
b(X) → a(X)

Q is empty.

(1) RFCMatchBoundsTRSProof (EQUIVALENT transformation)

Termination of the TRS R could be shown with a Match Bound [MATCHBOUNDS1,MATCHBOUNDS2] of 2. This implies Q-termination of R.
The following rules were used to construct the certificate:

f(f(X)) → f(a(b(f(X))))
f(a(g(X))) → b(X)
b(X) → a(X)

The certificate found is represented by the following graph.

The certificate consists of the following enumerated nodes:

1, 4, 8, 9, 10, 11, 12, 13

Node 1 is start node and node 4 is final node.

Those nodes are connected through the following edges:

  • 1 to 8 labelled f_1(0)
  • 1 to 4 labelled b_1(0), a_1(0), a_1(1)
  • 4 to 4 labelled #_1(0)
  • 8 to 9 labelled a_1(0)
  • 9 to 10 labelled b_1(0), a_1(1)
  • 10 to 4 labelled f_1(0), b_1(1), a_1(2)
  • 10 to 11 labelled f_1(1)
  • 11 to 12 labelled a_1(1)
  • 12 to 13 labelled b_1(1), a_1(2)
  • 13 to 4 labelled f_1(1), b_1(1), a_1(2)
  • 13 to 11 labelled f_1(1)

(2) YES