(0) Obligation:

Clauses:

star(U, []) :- !.
star([], W) :- ','(!, =(W, [])).
star(U, W) :- ','(app(U, V, W), star(U, V)).
app([], L, L).
app(.(X, L), M, .(X, N)) :- app(L, M, N).
=(X, X).

Query: star(g,g)

(1) BuiltinConflictTransformerProof (EQUIVALENT transformation)

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

(2) Obligation:

Clauses:

star(U, []) :- !.
star([], W) :- ','(!, user_defined_=(W, [])).
star(U, W) :- ','(app(U, V, W), star(U, V)).
app([], L, L).
app(.(X, L), M, .(X, N)) :- app(L, M, N).
user_defined_=(X, X).

Query: star(g,g)

(3) PrologToDTProblemTransformerProof (SOUND transformation)

Built DT problem from termination graph DT10.

(4) Obligation:

Triples:

appB(.(X1, X2), X3, .(X1, X4)) :- appB(X2, X3, X4).
starA(.(X1, X2), .(X1, X3)) :- appB(X2, X4, X3).
starA(.(X1, X2), .(X1, X3)) :- ','(appcB(X2, X4, X3), starA(.(X1, X2), X4)).

Clauses:

starcA(X1, []).
starcA(.(X1, X2), .(X1, X3)) :- ','(appcB(X2, X4, X3), starcA(.(X1, X2), X4)).
appcB([], X1, X1).
appcB(.(X1, X2), X3, .(X1, X4)) :- appcB(X2, X3, X4).

Afs:

starA(x1, x2)  =  starA(x1, x2)

(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:
starA_in: (b,b)
appB_in: (b,f,b)
appcB_in: (b,f,b)
Transforming TRIPLES into the following Term Rewriting System:
Pi DP problem:
The TRS P consists of the following rules:

STARA_IN_GG(.(X1, X2), .(X1, X3)) → U2_GG(X1, X2, X3, appB_in_gag(X2, X4, X3))
STARA_IN_GG(.(X1, X2), .(X1, X3)) → APPB_IN_GAG(X2, X4, X3)
APPB_IN_GAG(.(X1, X2), X3, .(X1, X4)) → U1_GAG(X1, X2, X3, X4, appB_in_gag(X2, X3, X4))
APPB_IN_GAG(.(X1, X2), X3, .(X1, X4)) → APPB_IN_GAG(X2, X3, X4)
STARA_IN_GG(.(X1, X2), .(X1, X3)) → U3_GG(X1, X2, X3, appcB_in_gag(X2, X4, X3))
U3_GG(X1, X2, X3, appcB_out_gag(X2, X4, X3)) → U4_GG(X1, X2, X3, starA_in_gg(.(X1, X2), X4))
U3_GG(X1, X2, X3, appcB_out_gag(X2, X4, X3)) → STARA_IN_GG(.(X1, X2), X4)

The TRS R consists of the following rules:

appcB_in_gag([], X1, X1) → appcB_out_gag([], X1, X1)
appcB_in_gag(.(X1, X2), X3, .(X1, X4)) → U8_gag(X1, X2, X3, X4, appcB_in_gag(X2, X3, X4))
U8_gag(X1, X2, X3, X4, appcB_out_gag(X2, X3, X4)) → appcB_out_gag(.(X1, X2), X3, .(X1, X4))

The argument filtering Pi contains the following mapping:
starA_in_gg(x1, x2)  =  starA_in_gg(x1, x2)
.(x1, x2)  =  .(x1, x2)
appB_in_gag(x1, x2, x3)  =  appB_in_gag(x1, x3)
appcB_in_gag(x1, x2, x3)  =  appcB_in_gag(x1, x3)
[]  =  []
appcB_out_gag(x1, x2, x3)  =  appcB_out_gag(x1, x2, x3)
U8_gag(x1, x2, x3, x4, x5)  =  U8_gag(x1, x2, x4, x5)
STARA_IN_GG(x1, x2)  =  STARA_IN_GG(x1, x2)
U2_GG(x1, x2, x3, x4)  =  U2_GG(x1, x2, x3, x4)
APPB_IN_GAG(x1, x2, x3)  =  APPB_IN_GAG(x1, x3)
U1_GAG(x1, x2, x3, x4, x5)  =  U1_GAG(x1, x2, x4, x5)
U3_GG(x1, x2, x3, x4)  =  U3_GG(x1, x2, x3, x4)
U4_GG(x1, x2, x3, x4)  =  U4_GG(x1, x2, x3, x4)

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:

STARA_IN_GG(.(X1, X2), .(X1, X3)) → U2_GG(X1, X2, X3, appB_in_gag(X2, X4, X3))
STARA_IN_GG(.(X1, X2), .(X1, X3)) → APPB_IN_GAG(X2, X4, X3)
APPB_IN_GAG(.(X1, X2), X3, .(X1, X4)) → U1_GAG(X1, X2, X3, X4, appB_in_gag(X2, X3, X4))
APPB_IN_GAG(.(X1, X2), X3, .(X1, X4)) → APPB_IN_GAG(X2, X3, X4)
STARA_IN_GG(.(X1, X2), .(X1, X3)) → U3_GG(X1, X2, X3, appcB_in_gag(X2, X4, X3))
U3_GG(X1, X2, X3, appcB_out_gag(X2, X4, X3)) → U4_GG(X1, X2, X3, starA_in_gg(.(X1, X2), X4))
U3_GG(X1, X2, X3, appcB_out_gag(X2, X4, X3)) → STARA_IN_GG(.(X1, X2), X4)

The TRS R consists of the following rules:

appcB_in_gag([], X1, X1) → appcB_out_gag([], X1, X1)
appcB_in_gag(.(X1, X2), X3, .(X1, X4)) → U8_gag(X1, X2, X3, X4, appcB_in_gag(X2, X3, X4))
U8_gag(X1, X2, X3, X4, appcB_out_gag(X2, X3, X4)) → appcB_out_gag(.(X1, X2), X3, .(X1, X4))

The argument filtering Pi contains the following mapping:
starA_in_gg(x1, x2)  =  starA_in_gg(x1, x2)
.(x1, x2)  =  .(x1, x2)
appB_in_gag(x1, x2, x3)  =  appB_in_gag(x1, x3)
appcB_in_gag(x1, x2, x3)  =  appcB_in_gag(x1, x3)
[]  =  []
appcB_out_gag(x1, x2, x3)  =  appcB_out_gag(x1, x2, x3)
U8_gag(x1, x2, x3, x4, x5)  =  U8_gag(x1, x2, x4, x5)
STARA_IN_GG(x1, x2)  =  STARA_IN_GG(x1, x2)
U2_GG(x1, x2, x3, x4)  =  U2_GG(x1, x2, x3, x4)
APPB_IN_GAG(x1, x2, x3)  =  APPB_IN_GAG(x1, x3)
U1_GAG(x1, x2, x3, x4, x5)  =  U1_GAG(x1, x2, x4, x5)
U3_GG(x1, x2, x3, x4)  =  U3_GG(x1, x2, x3, x4)
U4_GG(x1, x2, x3, x4)  =  U4_GG(x1, x2, x3, x4)

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

(7) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LOPSTR] contains 2 SCCs with 4 less nodes.

(8) Complex Obligation (AND)

(9) Obligation:

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

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

The TRS R consists of the following rules:

appcB_in_gag([], X1, X1) → appcB_out_gag([], X1, X1)
appcB_in_gag(.(X1, X2), X3, .(X1, X4)) → U8_gag(X1, X2, X3, X4, appcB_in_gag(X2, X3, X4))
U8_gag(X1, X2, X3, X4, appcB_out_gag(X2, X3, X4)) → appcB_out_gag(.(X1, X2), X3, .(X1, X4))

The argument filtering Pi contains the following mapping:
.(x1, x2)  =  .(x1, x2)
appcB_in_gag(x1, x2, x3)  =  appcB_in_gag(x1, x3)
[]  =  []
appcB_out_gag(x1, x2, x3)  =  appcB_out_gag(x1, x2, x3)
U8_gag(x1, x2, x3, x4, x5)  =  U8_gag(x1, x2, x4, x5)
APPB_IN_GAG(x1, x2, x3)  =  APPB_IN_GAG(x1, x3)

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

(10) UsableRulesProof (EQUIVALENT transformation)

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

(11) Obligation:

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

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

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

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

(12) PiDPToQDPProof (SOUND transformation)

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

(13) Obligation:

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

APPB_IN_GAG(.(X1, X2), .(X1, X4)) → APPB_IN_GAG(X2, X4)

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

(14) 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:

  • APPB_IN_GAG(.(X1, X2), .(X1, X4)) → APPB_IN_GAG(X2, X4)
    The graph contains the following edges 1 > 1, 2 > 2

(15) YES

(16) Obligation:

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

STARA_IN_GG(.(X1, X2), .(X1, X3)) → U3_GG(X1, X2, X3, appcB_in_gag(X2, X4, X3))
U3_GG(X1, X2, X3, appcB_out_gag(X2, X4, X3)) → STARA_IN_GG(.(X1, X2), X4)

The TRS R consists of the following rules:

appcB_in_gag([], X1, X1) → appcB_out_gag([], X1, X1)
appcB_in_gag(.(X1, X2), X3, .(X1, X4)) → U8_gag(X1, X2, X3, X4, appcB_in_gag(X2, X3, X4))
U8_gag(X1, X2, X3, X4, appcB_out_gag(X2, X3, X4)) → appcB_out_gag(.(X1, X2), X3, .(X1, X4))

The argument filtering Pi contains the following mapping:
.(x1, x2)  =  .(x1, x2)
appcB_in_gag(x1, x2, x3)  =  appcB_in_gag(x1, x3)
[]  =  []
appcB_out_gag(x1, x2, x3)  =  appcB_out_gag(x1, x2, x3)
U8_gag(x1, x2, x3, x4, x5)  =  U8_gag(x1, x2, x4, x5)
STARA_IN_GG(x1, x2)  =  STARA_IN_GG(x1, x2)
U3_GG(x1, x2, x3, x4)  =  U3_GG(x1, x2, x3, x4)

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

(17) PiDPToQDPProof (SOUND transformation)

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

(18) Obligation:

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

STARA_IN_GG(.(X1, X2), .(X1, X3)) → U3_GG(X1, X2, X3, appcB_in_gag(X2, X3))
U3_GG(X1, X2, X3, appcB_out_gag(X2, X4, X3)) → STARA_IN_GG(.(X1, X2), X4)

The TRS R consists of the following rules:

appcB_in_gag([], X1) → appcB_out_gag([], X1, X1)
appcB_in_gag(.(X1, X2), .(X1, X4)) → U8_gag(X1, X2, X4, appcB_in_gag(X2, X4))
U8_gag(X1, X2, X4, appcB_out_gag(X2, X3, X4)) → appcB_out_gag(.(X1, X2), X3, .(X1, X4))

The set Q consists of the following terms:

appcB_in_gag(x0, x1)
U8_gag(x0, x1, x2, x3)

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

(19) QDPOrderProof (EQUIVALENT transformation)

We use the reduction pair processor [LPAR04,JAR06].


The following pairs can be oriented strictly and are deleted.


STARA_IN_GG(.(X1, X2), .(X1, X3)) → U3_GG(X1, X2, X3, appcB_in_gag(X2, X3))
The remaining pairs can at least be oriented weakly.
Used ordering: Polynomial interpretation [POLO]:

POL(.(x1, x2)) = 1 + x2   
POL(STARA_IN_GG(x1, x2)) = x1 + x2   
POL(U3_GG(x1, x2, x3, x4)) = 1 + x4   
POL(U8_gag(x1, x2, x3, x4)) = 1 + x4   
POL([]) = 0   
POL(appcB_in_gag(x1, x2)) = x2   
POL(appcB_out_gag(x1, x2, x3)) = x1 + x2   

The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:

appcB_in_gag([], X1) → appcB_out_gag([], X1, X1)
appcB_in_gag(.(X1, X2), .(X1, X4)) → U8_gag(X1, X2, X4, appcB_in_gag(X2, X4))
U8_gag(X1, X2, X4, appcB_out_gag(X2, X3, X4)) → appcB_out_gag(.(X1, X2), X3, .(X1, X4))

(20) Obligation:

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

U3_GG(X1, X2, X3, appcB_out_gag(X2, X4, X3)) → STARA_IN_GG(.(X1, X2), X4)

The TRS R consists of the following rules:

appcB_in_gag([], X1) → appcB_out_gag([], X1, X1)
appcB_in_gag(.(X1, X2), .(X1, X4)) → U8_gag(X1, X2, X4, appcB_in_gag(X2, X4))
U8_gag(X1, X2, X4, appcB_out_gag(X2, X3, X4)) → appcB_out_gag(.(X1, X2), X3, .(X1, X4))

The set Q consists of the following terms:

appcB_in_gag(x0, x1)
U8_gag(x0, x1, x2, x3)

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

(21) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 1 less node.

(22) TRUE