(0) Obligation:

Clauses:

flat([], []).
flat(.([], T), R) :- flat(T, R).
flat(.(.(H, T), TT), .(H, R)) :- flat(.(T, TT), R).

Query: flat(g,a)

(1) PrologToDTProblemTransformerProof (SOUND transformation)

Built DT problem from termination graph DT10.

(2) Obligation:

Triples:

flatA(.([], .([], X1)), X2) :- flatA(X1, X2).
flatA(.([], .(.(X1, X2), X3)), .(X1, X4)) :- flatA(.(X2, X3), X4).
flatA(.(.(X1, []), X2), .(X1, X3)) :- flatA(X2, X3).
flatA(.(.(X1, .(X2, X3)), X4), .(X1, .(X2, X5))) :- flatA(.(X3, X4), X5).

Clauses:

flatcA([], []).
flatcA(.([], []), []).
flatcA(.([], .([], X1)), X2) :- flatcA(X1, X2).
flatcA(.([], .(.(X1, X2), X3)), .(X1, X4)) :- flatcA(.(X2, X3), X4).
flatcA(.(.(X1, []), X2), .(X1, X3)) :- flatcA(X2, X3).
flatcA(.(.(X1, .(X2, X3)), X4), .(X1, .(X2, X5))) :- flatcA(.(X3, X4), X5).

Afs:

flatA(x1, x2)  =  flatA(x1)

(3) TriplesToPiDPProof (SOUND transformation)

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

FLATA_IN_GA(.([], .([], X1)), X2) → U1_GA(X1, X2, flatA_in_ga(X1, X2))
FLATA_IN_GA(.([], .([], X1)), X2) → FLATA_IN_GA(X1, X2)
FLATA_IN_GA(.([], .(.(X1, X2), X3)), .(X1, X4)) → U2_GA(X1, X2, X3, X4, flatA_in_ga(.(X2, X3), X4))
FLATA_IN_GA(.([], .(.(X1, X2), X3)), .(X1, X4)) → FLATA_IN_GA(.(X2, X3), X4)
FLATA_IN_GA(.(.(X1, []), X2), .(X1, X3)) → U3_GA(X1, X2, X3, flatA_in_ga(X2, X3))
FLATA_IN_GA(.(.(X1, []), X2), .(X1, X3)) → FLATA_IN_GA(X2, X3)
FLATA_IN_GA(.(.(X1, .(X2, X3)), X4), .(X1, .(X2, X5))) → U4_GA(X1, X2, X3, X4, X5, flatA_in_ga(.(X3, X4), X5))
FLATA_IN_GA(.(.(X1, .(X2, X3)), X4), .(X1, .(X2, X5))) → FLATA_IN_GA(.(X3, X4), X5)

R is empty.
The argument filtering Pi contains the following mapping:
flatA_in_ga(x1, x2)  =  flatA_in_ga(x1)
.(x1, x2)  =  .(x1, x2)
[]  =  []
FLATA_IN_GA(x1, x2)  =  FLATA_IN_GA(x1)
U1_GA(x1, x2, x3)  =  U1_GA(x1, x3)
U2_GA(x1, x2, x3, x4, x5)  =  U2_GA(x1, x2, x3, x5)
U3_GA(x1, x2, x3, x4)  =  U3_GA(x1, x2, x4)
U4_GA(x1, x2, x3, x4, x5, x6)  =  U4_GA(x1, x2, x3, x4, x6)

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

Infinitary Constructor Rewriting Termination of PiDP implies Termination of TRIPLES

(4) Obligation:

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

FLATA_IN_GA(.([], .([], X1)), X2) → U1_GA(X1, X2, flatA_in_ga(X1, X2))
FLATA_IN_GA(.([], .([], X1)), X2) → FLATA_IN_GA(X1, X2)
FLATA_IN_GA(.([], .(.(X1, X2), X3)), .(X1, X4)) → U2_GA(X1, X2, X3, X4, flatA_in_ga(.(X2, X3), X4))
FLATA_IN_GA(.([], .(.(X1, X2), X3)), .(X1, X4)) → FLATA_IN_GA(.(X2, X3), X4)
FLATA_IN_GA(.(.(X1, []), X2), .(X1, X3)) → U3_GA(X1, X2, X3, flatA_in_ga(X2, X3))
FLATA_IN_GA(.(.(X1, []), X2), .(X1, X3)) → FLATA_IN_GA(X2, X3)
FLATA_IN_GA(.(.(X1, .(X2, X3)), X4), .(X1, .(X2, X5))) → U4_GA(X1, X2, X3, X4, X5, flatA_in_ga(.(X3, X4), X5))
FLATA_IN_GA(.(.(X1, .(X2, X3)), X4), .(X1, .(X2, X5))) → FLATA_IN_GA(.(X3, X4), X5)

R is empty.
The argument filtering Pi contains the following mapping:
flatA_in_ga(x1, x2)  =  flatA_in_ga(x1)
.(x1, x2)  =  .(x1, x2)
[]  =  []
FLATA_IN_GA(x1, x2)  =  FLATA_IN_GA(x1)
U1_GA(x1, x2, x3)  =  U1_GA(x1, x3)
U2_GA(x1, x2, x3, x4, x5)  =  U2_GA(x1, x2, x3, x5)
U3_GA(x1, x2, x3, x4)  =  U3_GA(x1, x2, x4)
U4_GA(x1, x2, x3, x4, x5, x6)  =  U4_GA(x1, x2, x3, x4, x6)

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

(5) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LOPSTR] contains 1 SCC with 4 less nodes.

(6) Obligation:

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

FLATA_IN_GA(.([], .(.(X1, X2), X3)), .(X1, X4)) → FLATA_IN_GA(.(X2, X3), X4)
FLATA_IN_GA(.([], .([], X1)), X2) → FLATA_IN_GA(X1, X2)
FLATA_IN_GA(.(.(X1, []), X2), .(X1, X3)) → FLATA_IN_GA(X2, X3)
FLATA_IN_GA(.(.(X1, .(X2, X3)), X4), .(X1, .(X2, X5))) → FLATA_IN_GA(.(X3, X4), X5)

R is empty.
The argument filtering Pi contains the following mapping:
.(x1, x2)  =  .(x1, x2)
[]  =  []
FLATA_IN_GA(x1, x2)  =  FLATA_IN_GA(x1)

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

(7) PiDPToQDPProof (SOUND transformation)

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

(8) Obligation:

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

FLATA_IN_GA(.([], .(.(X1, X2), X3))) → FLATA_IN_GA(.(X2, X3))
FLATA_IN_GA(.([], .([], X1))) → FLATA_IN_GA(X1)
FLATA_IN_GA(.(.(X1, []), X2)) → FLATA_IN_GA(X2)
FLATA_IN_GA(.(.(X1, .(X2, X3)), X4)) → FLATA_IN_GA(.(X3, X4))

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

(9) UsableRulesReductionPairsProof (EQUIVALENT transformation)

By using the usable rules with reduction pair processor [LPAR04] with a polynomial ordering [POLO], all dependency pairs and the corresponding usable rules [FROCOS05] can be oriented non-strictly. All non-usable rules are removed, and those dependency pairs and usable rules that have been oriented strictly or contain non-usable symbols in their left-hand side are removed as well.

The following dependency pairs can be deleted:

FLATA_IN_GA(.([], .(.(X1, X2), X3))) → FLATA_IN_GA(.(X2, X3))
FLATA_IN_GA(.([], .([], X1))) → FLATA_IN_GA(X1)
FLATA_IN_GA(.(.(X1, []), X2)) → FLATA_IN_GA(X2)
No rules are removed from R.

Used ordering: POLO with Polynomial interpretation [POLO]:

POL(.(x1, x2)) = 2·x1 + 2·x2   
POL(FLATA_IN_GA(x1)) = 2·x1   
POL([]) = 0   

(10) Obligation:

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

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

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

(11) MRRProof (EQUIVALENT transformation)

By using the rule removal processor [LPAR04] with the following ordering, at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented.
Strictly oriented dependency pairs:

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


Used ordering: Polynomial interpretation [POLO]:

POL(.(x1, x2)) = 1 + 2·x1 + 2·x2   
POL(FLATA_IN_GA(x1)) = 2·x1   

(12) Obligation:

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

(13) PisEmptyProof (EQUIVALENT transformation)

The TRS P is empty. Hence, there is no (P,Q,R) chain.

(14) YES