(0) Obligation:

Clauses:

append(X, Y, Z) :- ','(=(X, []), ','(!, =(Y, Z))).
append(X, Y, Z) :- ','(=(X, .(H, Xs)), ','(!, ','(=(Z, .(H, Zs)), append(Xs, Y, Zs)))).
=(X, X).

Query: append(g,a,a)

(1) BuiltinConflictTransformerProof (EQUIVALENT transformation)

Renamed defined predicates conflicting with built-in predicates [PROLOG].

(2) Obligation:

Clauses:

append(X, Y, Z) :- ','(user_defined_=(X, []), ','(!, user_defined_=(Y, Z))).
append(X, Y, Z) :- ','(user_defined_=(X, .(H, Xs)), ','(!, ','(user_defined_=(Z, .(H, Zs)), append(Xs, Y, Zs)))).
user_defined_=(X, X).

Query: append(g,a,a)

(3) PrologToDTProblemTransformerProof (SOUND transformation)

Built DT problem from termination graph DT10.

(4) Obligation:

Triples:

appendA(.(X1, X2), X3, .(X1, X4)) :- appendA(X2, X3, X4).

Clauses:

appendcA([], X1, X1).
appendcA(.(X1, X2), X3, .(X1, X4)) :- appendcA(X2, X3, X4).

Afs:

appendA(x1, x2, x3)  =  appendA(x1)

(5) TriplesToPiDPProof (SOUND transformation)

We use the technique of [DT09]. With regard to the inferred argument filtering the predicates were used in the following modes:
appendA_in: (b,f,f)
Transforming TRIPLES into the following Term Rewriting System:
Pi DP problem:
The TRS P consists of the following rules:

APPENDA_IN_GAA(.(X1, X2), X3, .(X1, X4)) → U1_GAA(X1, X2, X3, X4, appendA_in_gaa(X2, X3, X4))
APPENDA_IN_GAA(.(X1, X2), X3, .(X1, X4)) → APPENDA_IN_GAA(X2, X3, X4)

R is empty.
The argument filtering Pi contains the following mapping:
appendA_in_gaa(x1, x2, x3)  =  appendA_in_gaa(x1)
.(x1, x2)  =  .(x1, x2)
APPENDA_IN_GAA(x1, x2, x3)  =  APPENDA_IN_GAA(x1)
U1_GAA(x1, x2, x3, x4, x5)  =  U1_GAA(x1, x2, x5)

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

Infinitary Constructor Rewriting Termination of PiDP implies Termination of TRIPLES

(6) Obligation:

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

APPENDA_IN_GAA(.(X1, X2), X3, .(X1, X4)) → U1_GAA(X1, X2, X3, X4, appendA_in_gaa(X2, X3, X4))
APPENDA_IN_GAA(.(X1, X2), X3, .(X1, X4)) → APPENDA_IN_GAA(X2, X3, X4)

R is empty.
The argument filtering Pi contains the following mapping:
appendA_in_gaa(x1, x2, x3)  =  appendA_in_gaa(x1)
.(x1, x2)  =  .(x1, x2)
APPENDA_IN_GAA(x1, x2, x3)  =  APPENDA_IN_GAA(x1)
U1_GAA(x1, x2, x3, x4, x5)  =  U1_GAA(x1, x2, x5)

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

(7) DependencyGraphProof (EQUIVALENT transformation)

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

(8) Obligation:

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

APPENDA_IN_GAA(.(X1, X2), X3, .(X1, X4)) → APPENDA_IN_GAA(X2, X3, X4)

R is empty.
The argument filtering Pi contains the following mapping:
.(x1, x2)  =  .(x1, x2)
APPENDA_IN_GAA(x1, x2, x3)  =  APPENDA_IN_GAA(x1)

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

(9) PiDPToQDPProof (SOUND transformation)

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

(10) Obligation:

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

APPENDA_IN_GAA(.(X1, X2)) → APPENDA_IN_GAA(X2)

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

(11) QDPSizeChangeProof (EQUIVALENT transformation)

By using the subterm criterion [SUBTERM_CRITERION] together with the size-change analysis [AAECC05] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:

  • APPENDA_IN_GAA(.(X1, X2)) → APPENDA_IN_GAA(X2)
    The graph contains the following edges 1 > 1

(12) YES