(0) Obligation:
Clauses:
fl([], [], 0).
fl(.(E, X), R, s(Z)) :- ','(append(E, Y, R), fl(X, Y, Z)).
append([], X, X).
append(.(X, Xs), Ys, .(X, Zs)) :- append(Xs, Ys, Zs).
Queries:
fl(g,a,g).
(1) PrologToPiTRSProof (SOUND transformation)
We use the technique of [LOPSTR]. With regard to the inferred argument filtering the predicates were used in the following modes:
fl_in: (b,f,b)
append_in: (b,f,f)
Transforming 
Prolog into the following 
Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag(
x1, 
x3)
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x1, 
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa(
x1)
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x1, 
x2, 
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x1, 
x2, 
x4, 
x5)
Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog
 
(2) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag(
x1, 
x3)
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x1, 
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa(
x1)
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x1, 
x2, 
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x1, 
x2, 
x4, 
x5)
 
(3) 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:
FL_IN_GAG(.(E, X), R, s(Z)) → U1_GAG(E, X, R, Z, append_in_gaa(E, Y, R))
FL_IN_GAG(.(E, X), R, s(Z)) → APPEND_IN_GAA(E, Y, R)
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → U3_GAA(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → APPEND_IN_GAA(Xs, Ys, Zs)
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_GAG(E, X, R, Z, fl_in_gag(X, Y, Z))
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → FL_IN_GAG(X, Y, Z)
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag(
x1, 
x3)
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x1, 
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa(
x1)
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x1, 
x2, 
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x1, 
x2, 
x4, 
x5)
FL_IN_GAG(
x1, 
x2, 
x3)  =  
FL_IN_GAG(
x1, 
x3)
U1_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_GAG(
x1, 
x2, 
x4, 
x5)
APPEND_IN_GAA(
x1, 
x2, 
x3)  =  
APPEND_IN_GAA(
x1)
U3_GAA(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_GAA(
x1, 
x2, 
x5)
U2_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_GAG(
x1, 
x2, 
x4, 
x5)
We have to consider all (P,R,Pi)-chains
 
(4) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
FL_IN_GAG(.(E, X), R, s(Z)) → U1_GAG(E, X, R, Z, append_in_gaa(E, Y, R))
FL_IN_GAG(.(E, X), R, s(Z)) → APPEND_IN_GAA(E, Y, R)
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → U3_GAA(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → APPEND_IN_GAA(Xs, Ys, Zs)
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_GAG(E, X, R, Z, fl_in_gag(X, Y, Z))
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → FL_IN_GAG(X, Y, Z)
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag(
x1, 
x3)
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x1, 
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa(
x1)
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x1, 
x2, 
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x1, 
x2, 
x4, 
x5)
FL_IN_GAG(
x1, 
x2, 
x3)  =  
FL_IN_GAG(
x1, 
x3)
U1_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_GAG(
x1, 
x2, 
x4, 
x5)
APPEND_IN_GAA(
x1, 
x2, 
x3)  =  
APPEND_IN_GAA(
x1)
U3_GAA(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_GAA(
x1, 
x2, 
x5)
U2_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_GAG(
x1, 
x2, 
x4, 
x5)
We have to consider all (P,R,Pi)-chains
 
(5) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LOPSTR] contains 2 SCCs with 3 less nodes.
(6) Complex Obligation (AND)
(7) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → APPEND_IN_GAA(Xs, Ys, Zs)
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag(
x1, 
x3)
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x1, 
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa(
x1)
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x1, 
x2, 
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x1, 
x2, 
x4, 
x5)
APPEND_IN_GAA(
x1, 
x2, 
x3)  =  
APPEND_IN_GAA(
x1)
We have to consider all (P,R,Pi)-chains
 
(8) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(9) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → APPEND_IN_GAA(Xs, Ys, Zs)
R is empty.
The argument filtering Pi contains the following mapping:
.(
x1, 
x2)  =  
.(
x1, 
x2)
APPEND_IN_GAA(
x1, 
x2, 
x3)  =  
APPEND_IN_GAA(
x1)
We have to consider all (P,R,Pi)-chains
 
(10) PiDPToQDPProof (SOUND transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(11) Obligation:
Q DP problem:
The TRS P consists of the following rules:
APPEND_IN_GAA(.(X, Xs)) → APPEND_IN_GAA(Xs)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
 
(12) 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:
- APPEND_IN_GAA(.(X, Xs)) → APPEND_IN_GAA(Xs)
The graph contains the following edges 1 > 1 
 
(13) TRUE
(14) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → FL_IN_GAG(X, Y, Z)
FL_IN_GAG(.(E, X), R, s(Z)) → U1_GAG(E, X, R, Z, append_in_gaa(E, Y, R))
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag(
x1, 
x3)
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x1, 
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa(
x1)
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x1, 
x2, 
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x1, 
x2, 
x4, 
x5)
FL_IN_GAG(
x1, 
x2, 
x3)  =  
FL_IN_GAG(
x1, 
x3)
U1_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_GAG(
x1, 
x2, 
x4, 
x5)
We have to consider all (P,R,Pi)-chains
 
(15) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(16) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → FL_IN_GAG(X, Y, Z)
FL_IN_GAG(.(E, X), R, s(Z)) → U1_GAG(E, X, R, Z, append_in_gaa(E, Y, R))
The TRS R consists of the following rules:
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
The argument filtering Pi contains the following mapping:
[]  =  
[]
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa(
x1)
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x1, 
x2, 
x5)
FL_IN_GAG(
x1, 
x2, 
x3)  =  
FL_IN_GAG(
x1, 
x3)
U1_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_GAG(
x1, 
x2, 
x4, 
x5)
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:
U1_GAG(E, X, Z, append_out_gaa(E)) → FL_IN_GAG(X, Z)
FL_IN_GAG(.(E, X), s(Z)) → U1_GAG(E, X, Z, append_in_gaa(E))
The TRS R consists of the following rules:
append_in_gaa([]) → append_out_gaa([])
append_in_gaa(.(X, Xs)) → U3_gaa(X, Xs, append_in_gaa(Xs))
U3_gaa(X, Xs, append_out_gaa(Xs)) → append_out_gaa(.(X, Xs))
The set Q consists of the following terms:
append_in_gaa(x0)
U3_gaa(x0, x1, x2)
We have to consider all (P,Q,R)-chains.
 
(19) 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:
- FL_IN_GAG(.(E, X), s(Z)) → U1_GAG(E, X, Z, append_in_gaa(E))
The graph contains the following edges 1 > 1, 1 > 2, 2 > 3 
- U1_GAG(E, X, Z, append_out_gaa(E)) → FL_IN_GAG(X, Z)
The graph contains the following edges 2 >= 1, 3 >= 2 
 
(20) TRUE
(21) PrologToPiTRSProof (SOUND transformation)
We use the technique of [LOPSTR]. With regard to the inferred argument filtering the predicates were used in the following modes:
fl_in: (b,f,b)
append_in: (b,f,f)
Transforming 
Prolog into the following 
Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x5)
Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog
 
(22) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x5)
 
(23) 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:
FL_IN_GAG(.(E, X), R, s(Z)) → U1_GAG(E, X, R, Z, append_in_gaa(E, Y, R))
FL_IN_GAG(.(E, X), R, s(Z)) → APPEND_IN_GAA(E, Y, R)
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → U3_GAA(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → APPEND_IN_GAA(Xs, Ys, Zs)
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_GAG(E, X, R, Z, fl_in_gag(X, Y, Z))
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → FL_IN_GAG(X, Y, Z)
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x5)
FL_IN_GAG(
x1, 
x2, 
x3)  =  
FL_IN_GAG(
x1, 
x3)
U1_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_GAG(
x2, 
x4, 
x5)
APPEND_IN_GAA(
x1, 
x2, 
x3)  =  
APPEND_IN_GAA(
x1)
U3_GAA(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_GAA(
x5)
U2_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_GAG(
x5)
We have to consider all (P,R,Pi)-chains
 
(24) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
FL_IN_GAG(.(E, X), R, s(Z)) → U1_GAG(E, X, R, Z, append_in_gaa(E, Y, R))
FL_IN_GAG(.(E, X), R, s(Z)) → APPEND_IN_GAA(E, Y, R)
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → U3_GAA(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → APPEND_IN_GAA(Xs, Ys, Zs)
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_GAG(E, X, R, Z, fl_in_gag(X, Y, Z))
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → FL_IN_GAG(X, Y, Z)
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x5)
FL_IN_GAG(
x1, 
x2, 
x3)  =  
FL_IN_GAG(
x1, 
x3)
U1_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_GAG(
x2, 
x4, 
x5)
APPEND_IN_GAA(
x1, 
x2, 
x3)  =  
APPEND_IN_GAA(
x1)
U3_GAA(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_GAA(
x5)
U2_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_GAG(
x5)
We have to consider all (P,R,Pi)-chains
 
(25) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LOPSTR] contains 2 SCCs with 3 less nodes.
(26) Complex Obligation (AND)
(27) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → APPEND_IN_GAA(Xs, Ys, Zs)
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x5)
APPEND_IN_GAA(
x1, 
x2, 
x3)  =  
APPEND_IN_GAA(
x1)
We have to consider all (P,R,Pi)-chains
 
(28) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(29) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
APPEND_IN_GAA(.(X, Xs), Ys, .(X, Zs)) → APPEND_IN_GAA(Xs, Ys, Zs)
R is empty.
The argument filtering Pi contains the following mapping:
.(
x1, 
x2)  =  
.(
x1, 
x2)
APPEND_IN_GAA(
x1, 
x2, 
x3)  =  
APPEND_IN_GAA(
x1)
We have to consider all (P,R,Pi)-chains
 
(30) PiDPToQDPProof (SOUND transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(31) Obligation:
Q DP problem:
The TRS P consists of the following rules:
APPEND_IN_GAA(.(X, Xs)) → APPEND_IN_GAA(Xs)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
 
(32) 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:
- APPEND_IN_GAA(.(X, Xs)) → APPEND_IN_GAA(Xs)
The graph contains the following edges 1 > 1 
 
(33) TRUE
(34) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → FL_IN_GAG(X, Y, Z)
FL_IN_GAG(.(E, X), R, s(Z)) → U1_GAG(E, X, R, Z, append_in_gaa(E, Y, R))
The TRS R consists of the following rules:
fl_in_gag([], [], 0) → fl_out_gag([], [], 0)
fl_in_gag(.(E, X), R, s(Z)) → U1_gag(E, X, R, Z, append_in_gaa(E, Y, R))
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
U1_gag(E, X, R, Z, append_out_gaa(E, Y, R)) → U2_gag(E, X, R, Z, fl_in_gag(X, Y, Z))
U2_gag(E, X, R, Z, fl_out_gag(X, Y, Z)) → fl_out_gag(.(E, X), R, s(Z))
The argument filtering Pi contains the following mapping:
fl_in_gag(
x1, 
x2, 
x3)  =  
fl_in_gag(
x1, 
x3)
[]  =  
[]
0  =  
0
fl_out_gag(
x1, 
x2, 
x3)  =  
fl_out_gag
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
U1_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_gag(
x2, 
x4, 
x5)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x5)
U2_gag(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U2_gag(
x5)
FL_IN_GAG(
x1, 
x2, 
x3)  =  
FL_IN_GAG(
x1, 
x3)
U1_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_GAG(
x2, 
x4, 
x5)
We have to consider all (P,R,Pi)-chains
 
(35) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(36) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
U1_GAG(E, X, R, Z, append_out_gaa(E, Y, R)) → FL_IN_GAG(X, Y, Z)
FL_IN_GAG(.(E, X), R, s(Z)) → U1_GAG(E, X, R, Z, append_in_gaa(E, Y, R))
The TRS R consists of the following rules:
append_in_gaa([], X, X) → append_out_gaa([], X, X)
append_in_gaa(.(X, Xs), Ys, .(X, Zs)) → U3_gaa(X, Xs, Ys, Zs, append_in_gaa(Xs, Ys, Zs))
U3_gaa(X, Xs, Ys, Zs, append_out_gaa(Xs, Ys, Zs)) → append_out_gaa(.(X, Xs), Ys, .(X, Zs))
The argument filtering Pi contains the following mapping:
[]  =  
[]
.(
x1, 
x2)  =  
.(
x1, 
x2)
s(
x1)  =  
s(
x1)
append_in_gaa(
x1, 
x2, 
x3)  =  
append_in_gaa(
x1)
append_out_gaa(
x1, 
x2, 
x3)  =  
append_out_gaa
U3_gaa(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U3_gaa(
x5)
FL_IN_GAG(
x1, 
x2, 
x3)  =  
FL_IN_GAG(
x1, 
x3)
U1_GAG(
x1, 
x2, 
x3, 
x4, 
x5)  =  
U1_GAG(
x2, 
x4, 
x5)
We have to consider all (P,R,Pi)-chains
 
(37) PiDPToQDPProof (SOUND transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(38) Obligation:
Q DP problem:
The TRS P consists of the following rules:
U1_GAG(X, Z, append_out_gaa) → FL_IN_GAG(X, Z)
FL_IN_GAG(.(E, X), s(Z)) → U1_GAG(X, Z, append_in_gaa(E))
The TRS R consists of the following rules:
append_in_gaa([]) → append_out_gaa
append_in_gaa(.(X, Xs)) → U3_gaa(append_in_gaa(Xs))
U3_gaa(append_out_gaa) → append_out_gaa
The set Q consists of the following terms:
append_in_gaa(x0)
U3_gaa(x0)
We have to consider all (P,Q,R)-chains.