Left Termination of the query pattern f_in_1(a) w.r.t. the given Prolog program could not be shown:

0 Prolog
↳1 CutEliminatorProof (⇐)
↳2 Prolog
  ↳3 PrologToPiTRSProof (⇐)
    ↳4 PiTRS
    ↳5 DependencyPairsProof (⇔)
    ↳6 PiDP
    ↳7 DependencyGraphProof (⇔)
    ↳8 PiDP
    ↳9 UsableRulesProof (⇔)
    ↳10 PiDP
    ↳11 PiDPToQDPProof (⇔)
    ↳12 QDP
      ↳13 Instantiation (⇔)
        ↳14 QDP
      ↳15 Instantiation (⇔)
        ↳16 QDP
        ↳17 NonTerminationProof (⇔)
        ↳18 FALSE
  ↳19 PrologToPiTRSProof (⇐)
    ↳20 PiTRS
    ↳21 DependencyPairsProof (⇔)
    ↳22 PiDP
    ↳23 DependencyGraphProof (⇔)
    ↳24 PiDP
    ↳25 UsableRulesProof (⇔)
    ↳26 PiDP
    ↳27 PiDPToQDPProof (⇔)
    ↳28 QDP
      ↳29 Instantiation (⇔)
        ↳30 QDP
      ↳31 Instantiation (⇔)
        ↳32 QDP
        ↳33 NonTerminationProof (⇔)
        ↳34 FALSE

(0) Obligation:

Clauses:

f(X) :- ','(p(X), q(X)).
p(a).
p(X) :- ','(p(a), !).
q(b).

Queries:

f(a).

(1) CutEliminatorProof (SOUND transformation)

Eliminated all cuts by simply ignoring them[PROLOG].

(2) Obligation:

Clauses:

f(X) :- ','(p(X), q(X)).
p(a).
p(X) :- p(a).
q(b).

Queries:

f(a).

(3) PrologToPiTRSProof (SOUND transformation)

We use the technique of [LOPSTR]. With regard to the inferred argument filtering the predicates were used in the following modes:
f_in: (f)
p_in: (f) (b)
Transforming Prolog into the following Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g
U3_g(x1, x2)  =  U3_g(x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)

Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog

(4) Obligation:

Pi-finite rewrite system:
The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g
U3_g(x1, x2)  =  U3_g(x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)

(5) DependencyPairsProof (EQUIVALENT transformation)

Using Dependency Pairs [AG00,LOPSTR] we result in the following initial DP problem:
Pi DP problem:
The TRS P consists of the following rules:

F_IN_A(X) → U1_A(X, p_in_a(X))
F_IN_A(X) → P_IN_A(X)
P_IN_A(X) → U3_A(X, p_in_g(a))
P_IN_A(X) → P_IN_G(a)
P_IN_G(X) → U3_G(X, p_in_g(a))
P_IN_G(X) → P_IN_G(a)
U1_A(X, p_out_a(X)) → U2_A(X, q_in_a(X))
U1_A(X, p_out_a(X)) → Q_IN_A(X)

The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g
U3_g(x1, x2)  =  U3_g(x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)
F_IN_A(x1)  =  F_IN_A
U1_A(x1, x2)  =  U1_A(x2)
P_IN_A(x1)  =  P_IN_A
U3_A(x1, x2)  =  U3_A(x2)
P_IN_G(x1)  =  P_IN_G(x1)
U3_G(x1, x2)  =  U3_G(x2)
U2_A(x1, x2)  =  U2_A(x2)
Q_IN_A(x1)  =  Q_IN_A

We have to consider all (P,R,Pi)-chains

(6) Obligation:

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

F_IN_A(X) → U1_A(X, p_in_a(X))
F_IN_A(X) → P_IN_A(X)
P_IN_A(X) → U3_A(X, p_in_g(a))
P_IN_A(X) → P_IN_G(a)
P_IN_G(X) → U3_G(X, p_in_g(a))
P_IN_G(X) → P_IN_G(a)
U1_A(X, p_out_a(X)) → U2_A(X, q_in_a(X))
U1_A(X, p_out_a(X)) → Q_IN_A(X)

The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g
U3_g(x1, x2)  =  U3_g(x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)
F_IN_A(x1)  =  F_IN_A
U1_A(x1, x2)  =  U1_A(x2)
P_IN_A(x1)  =  P_IN_A
U3_A(x1, x2)  =  U3_A(x2)
P_IN_G(x1)  =  P_IN_G(x1)
U3_G(x1, x2)  =  U3_G(x2)
U2_A(x1, x2)  =  U2_A(x2)
Q_IN_A(x1)  =  Q_IN_A

We have to consider all (P,R,Pi)-chains

(7) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LOPSTR] contains 1 SCC with 7 less nodes.

(8) Obligation:

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

P_IN_G(X) → P_IN_G(a)

The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g
U3_g(x1, x2)  =  U3_g(x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)
P_IN_G(x1)  =  P_IN_G(x1)

We have to consider all (P,R,Pi)-chains

(9) UsableRulesProof (EQUIVALENT transformation)

For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.

(10) Obligation:

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

P_IN_G(X) → P_IN_G(a)

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

(11) PiDPToQDPProof (EQUIVALENT transformation)

Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.

(12) Obligation:

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

P_IN_G(X) → P_IN_G(a)

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

(13) Instantiation (EQUIVALENT transformation)

By instantiating [LPAR04] the rule P_IN_G(X) → P_IN_G(a) we obtained the following new rules [LPAR04]:

P_IN_G(a) → P_IN_G(a)

(14) Obligation:

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

P_IN_G(a) → P_IN_G(a)

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

(15) Instantiation (EQUIVALENT transformation)

By instantiating [LPAR04] the rule P_IN_G(X) → P_IN_G(a) we obtained the following new rules [LPAR04]:

P_IN_G(a) → P_IN_G(a)

(16) Obligation:

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

P_IN_G(a) → P_IN_G(a)

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

(17) NonTerminationProof (EQUIVALENT transformation)

We used the non-termination processor [FROCOS05] to show that the DP problem is infinite.
Found a loop by semiunifying a rule from P directly.

s = P_IN_G(a) evaluates to t =P_IN_G(a)

Thus s starts an infinite chain as s semiunifies with t with the following substitutions:
  • Semiunifier: [ ]
  • Matcher: [ ]



Rewriting sequence

The DP semiunifies directly so there is only one rewrite step from P_IN_G(a) to P_IN_G(a).



(18) FALSE

(19) PrologToPiTRSProof (SOUND transformation)

We use the technique of [LOPSTR]. With regard to the inferred argument filtering the predicates were used in the following modes:
f_in: (f)
p_in: (f) (b)
Transforming Prolog into the following Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g(x1)
U3_g(x1, x2)  =  U3_g(x1, x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)

Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog

(20) Obligation:

Pi-finite rewrite system:
The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g(x1)
U3_g(x1, x2)  =  U3_g(x1, x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)

(21) DependencyPairsProof (EQUIVALENT transformation)

Using Dependency Pairs [AG00,LOPSTR] we result in the following initial DP problem:
Pi DP problem:
The TRS P consists of the following rules:

F_IN_A(X) → U1_A(X, p_in_a(X))
F_IN_A(X) → P_IN_A(X)
P_IN_A(X) → U3_A(X, p_in_g(a))
P_IN_A(X) → P_IN_G(a)
P_IN_G(X) → U3_G(X, p_in_g(a))
P_IN_G(X) → P_IN_G(a)
U1_A(X, p_out_a(X)) → U2_A(X, q_in_a(X))
U1_A(X, p_out_a(X)) → Q_IN_A(X)

The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g(x1)
U3_g(x1, x2)  =  U3_g(x1, x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)
F_IN_A(x1)  =  F_IN_A
U1_A(x1, x2)  =  U1_A(x2)
P_IN_A(x1)  =  P_IN_A
U3_A(x1, x2)  =  U3_A(x2)
P_IN_G(x1)  =  P_IN_G(x1)
U3_G(x1, x2)  =  U3_G(x1, x2)
U2_A(x1, x2)  =  U2_A(x2)
Q_IN_A(x1)  =  Q_IN_A

We have to consider all (P,R,Pi)-chains

(22) Obligation:

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

F_IN_A(X) → U1_A(X, p_in_a(X))
F_IN_A(X) → P_IN_A(X)
P_IN_A(X) → U3_A(X, p_in_g(a))
P_IN_A(X) → P_IN_G(a)
P_IN_G(X) → U3_G(X, p_in_g(a))
P_IN_G(X) → P_IN_G(a)
U1_A(X, p_out_a(X)) → U2_A(X, q_in_a(X))
U1_A(X, p_out_a(X)) → Q_IN_A(X)

The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g(x1)
U3_g(x1, x2)  =  U3_g(x1, x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)
F_IN_A(x1)  =  F_IN_A
U1_A(x1, x2)  =  U1_A(x2)
P_IN_A(x1)  =  P_IN_A
U3_A(x1, x2)  =  U3_A(x2)
P_IN_G(x1)  =  P_IN_G(x1)
U3_G(x1, x2)  =  U3_G(x1, x2)
U2_A(x1, x2)  =  U2_A(x2)
Q_IN_A(x1)  =  Q_IN_A

We have to consider all (P,R,Pi)-chains

(23) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LOPSTR] contains 1 SCC with 7 less nodes.

(24) Obligation:

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

P_IN_G(X) → P_IN_G(a)

The TRS R consists of the following rules:

f_in_a(X) → U1_a(X, p_in_a(X))
p_in_a(a) → p_out_a(a)
p_in_a(X) → U3_a(X, p_in_g(a))
p_in_g(a) → p_out_g(a)
p_in_g(X) → U3_g(X, p_in_g(a))
U3_g(X, p_out_g(a)) → p_out_g(X)
U3_a(X, p_out_g(a)) → p_out_a(X)
U1_a(X, p_out_a(X)) → U2_a(X, q_in_a(X))
q_in_a(b) → q_out_a(b)
U2_a(X, q_out_a(X)) → f_out_a(X)

The argument filtering Pi contains the following mapping:
f_in_a(x1)  =  f_in_a
U1_a(x1, x2)  =  U1_a(x2)
p_in_a(x1)  =  p_in_a
p_out_a(x1)  =  p_out_a
U3_a(x1, x2)  =  U3_a(x2)
p_in_g(x1)  =  p_in_g(x1)
a  =  a
p_out_g(x1)  =  p_out_g(x1)
U3_g(x1, x2)  =  U3_g(x1, x2)
U2_a(x1, x2)  =  U2_a(x2)
q_in_a(x1)  =  q_in_a
q_out_a(x1)  =  q_out_a(x1)
f_out_a(x1)  =  f_out_a(x1)
P_IN_G(x1)  =  P_IN_G(x1)

We have to consider all (P,R,Pi)-chains

(25) UsableRulesProof (EQUIVALENT transformation)

For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.

(26) Obligation:

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

P_IN_G(X) → P_IN_G(a)

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

(27) PiDPToQDPProof (EQUIVALENT transformation)

Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.

(28) Obligation:

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

P_IN_G(X) → P_IN_G(a)

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

(29) Instantiation (EQUIVALENT transformation)

By instantiating [LPAR04] the rule P_IN_G(X) → P_IN_G(a) we obtained the following new rules [LPAR04]:

P_IN_G(a) → P_IN_G(a)

(30) Obligation:

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

P_IN_G(a) → P_IN_G(a)

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

(31) Instantiation (EQUIVALENT transformation)

By instantiating [LPAR04] the rule P_IN_G(X) → P_IN_G(a) we obtained the following new rules [LPAR04]:

P_IN_G(a) → P_IN_G(a)

(32) Obligation:

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

P_IN_G(a) → P_IN_G(a)

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

(33) NonTerminationProof (EQUIVALENT transformation)

We used the non-termination processor [FROCOS05] to show that the DP problem is infinite.
Found a loop by semiunifying a rule from P directly.

s = P_IN_G(a) evaluates to t =P_IN_G(a)

Thus s starts an infinite chain as s semiunifies with t with the following substitutions:
  • Matcher: [ ]
  • Semiunifier: [ ]



Rewriting sequence

The DP semiunifies directly so there is only one rewrite step from P_IN_G(a) to P_IN_G(a).



(34) FALSE