Left Termination of the query pattern samefringe(b,b) w.r.t. the given Prolog program could successfully be proven:



PROLOG
  ↳ PrologToPiTRSProof

gopher2(nil0, nil0).
gopher2(cons2(nil0, Y), cons2(nil0, Y)).
gopher2(cons2(cons2(U, V), W), X) :- gopher2(cons2(U, cons2(V, W)), X).
samefringe2(nil0, nil0).
samefringe2(cons2(U, V), cons2(X, Y)) :- gopher2(cons2(U, V), cons2(U1, V1)), gopher2(cons2(X, Y), cons2(X1, Y1)), samefringe2(V1, Y1).


With regard to the inferred argument filtering the predicates were used in the following modes:
samefringe2: (b,b)
gopher2: (b,f)
Transforming PROLOG into the following Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:


samefringe_2_in_gg2(nil_0, nil_0) -> samefringe_2_out_gg2(nil_0, nil_0)
samefringe_2_in_gg2(cons_22(U, V), cons_22(X, Y)) -> if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
gopher_2_in_ga2(nil_0, nil_0) -> gopher_2_out_ga2(nil_0, nil_0)
gopher_2_in_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y)) -> gopher_2_out_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y))
gopher_2_in_ga2(cons_22(cons_22(U, V), W), X) -> if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_out_ga2(cons_22(U, cons_22(V, W)), X)) -> gopher_2_out_ga2(cons_22(cons_22(U, V), W), X)
if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_in_gg2(V1, Y1))
if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_out_gg2(V1, Y1)) -> samefringe_2_out_gg2(cons_22(U, V), cons_22(X, Y))

The argument filtering Pi contains the following mapping:
samefringe_2_in_gg2(x1, x2)  =  samefringe_2_in_gg2(x1, x2)
nil_0  =  nil_0
cons_22(x1, x2)  =  cons_22(x1, x2)
samefringe_2_out_gg2(x1, x2)  =  samefringe_2_out_gg
if_samefringe_2_in_1_gg5(x1, x2, x3, x4, x5)  =  if_samefringe_2_in_1_gg3(x3, x4, x5)
gopher_2_in_ga2(x1, x2)  =  gopher_2_in_ga1(x1)
gopher_2_out_ga2(x1, x2)  =  gopher_2_out_ga1(x2)
if_gopher_2_in_1_ga5(x1, x2, x3, x4, x5)  =  if_gopher_2_in_1_ga1(x5)
if_samefringe_2_in_2_gg6(x1, x2, x3, x4, x5, x6)  =  if_samefringe_2_in_2_gg2(x5, x6)
if_samefringe_2_in_3_gg7(x1, x2, x3, x4, x5, x6, x7)  =  if_samefringe_2_in_3_gg1(x7)

Infinitary Constructor Rewriting Termination of PiTRS implies Termination of PROLOG



↳ PROLOG
  ↳ PrologToPiTRSProof
PiTRS
      ↳ DependencyPairsProof

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

samefringe_2_in_gg2(nil_0, nil_0) -> samefringe_2_out_gg2(nil_0, nil_0)
samefringe_2_in_gg2(cons_22(U, V), cons_22(X, Y)) -> if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
gopher_2_in_ga2(nil_0, nil_0) -> gopher_2_out_ga2(nil_0, nil_0)
gopher_2_in_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y)) -> gopher_2_out_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y))
gopher_2_in_ga2(cons_22(cons_22(U, V), W), X) -> if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_out_ga2(cons_22(U, cons_22(V, W)), X)) -> gopher_2_out_ga2(cons_22(cons_22(U, V), W), X)
if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_in_gg2(V1, Y1))
if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_out_gg2(V1, Y1)) -> samefringe_2_out_gg2(cons_22(U, V), cons_22(X, Y))

The argument filtering Pi contains the following mapping:
samefringe_2_in_gg2(x1, x2)  =  samefringe_2_in_gg2(x1, x2)
nil_0  =  nil_0
cons_22(x1, x2)  =  cons_22(x1, x2)
samefringe_2_out_gg2(x1, x2)  =  samefringe_2_out_gg
if_samefringe_2_in_1_gg5(x1, x2, x3, x4, x5)  =  if_samefringe_2_in_1_gg3(x3, x4, x5)
gopher_2_in_ga2(x1, x2)  =  gopher_2_in_ga1(x1)
gopher_2_out_ga2(x1, x2)  =  gopher_2_out_ga1(x2)
if_gopher_2_in_1_ga5(x1, x2, x3, x4, x5)  =  if_gopher_2_in_1_ga1(x5)
if_samefringe_2_in_2_gg6(x1, x2, x3, x4, x5, x6)  =  if_samefringe_2_in_2_gg2(x5, x6)
if_samefringe_2_in_3_gg7(x1, x2, x3, x4, x5, x6, x7)  =  if_samefringe_2_in_3_gg1(x7)


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

SAMEFRINGE_2_IN_GG2(cons_22(U, V), cons_22(X, Y)) -> IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
SAMEFRINGE_2_IN_GG2(cons_22(U, V), cons_22(X, Y)) -> GOPHER_2_IN_GA2(cons_22(U, V), cons_22(U1, V1))
GOPHER_2_IN_GA2(cons_22(cons_22(U, V), W), X) -> IF_GOPHER_2_IN_1_GA5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
GOPHER_2_IN_GA2(cons_22(cons_22(U, V), W), X) -> GOPHER_2_IN_GA2(cons_22(U, cons_22(V, W)), X)
IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> GOPHER_2_IN_GA2(cons_22(X, Y), cons_22(X1, Y1))
IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> IF_SAMEFRINGE_2_IN_3_GG7(U, V, X, Y, V1, Y1, samefringe_2_in_gg2(V1, Y1))
IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> SAMEFRINGE_2_IN_GG2(V1, Y1)

The TRS R consists of the following rules:

samefringe_2_in_gg2(nil_0, nil_0) -> samefringe_2_out_gg2(nil_0, nil_0)
samefringe_2_in_gg2(cons_22(U, V), cons_22(X, Y)) -> if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
gopher_2_in_ga2(nil_0, nil_0) -> gopher_2_out_ga2(nil_0, nil_0)
gopher_2_in_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y)) -> gopher_2_out_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y))
gopher_2_in_ga2(cons_22(cons_22(U, V), W), X) -> if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_out_ga2(cons_22(U, cons_22(V, W)), X)) -> gopher_2_out_ga2(cons_22(cons_22(U, V), W), X)
if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_in_gg2(V1, Y1))
if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_out_gg2(V1, Y1)) -> samefringe_2_out_gg2(cons_22(U, V), cons_22(X, Y))

The argument filtering Pi contains the following mapping:
samefringe_2_in_gg2(x1, x2)  =  samefringe_2_in_gg2(x1, x2)
nil_0  =  nil_0
cons_22(x1, x2)  =  cons_22(x1, x2)
samefringe_2_out_gg2(x1, x2)  =  samefringe_2_out_gg
if_samefringe_2_in_1_gg5(x1, x2, x3, x4, x5)  =  if_samefringe_2_in_1_gg3(x3, x4, x5)
gopher_2_in_ga2(x1, x2)  =  gopher_2_in_ga1(x1)
gopher_2_out_ga2(x1, x2)  =  gopher_2_out_ga1(x2)
if_gopher_2_in_1_ga5(x1, x2, x3, x4, x5)  =  if_gopher_2_in_1_ga1(x5)
if_samefringe_2_in_2_gg6(x1, x2, x3, x4, x5, x6)  =  if_samefringe_2_in_2_gg2(x5, x6)
if_samefringe_2_in_3_gg7(x1, x2, x3, x4, x5, x6, x7)  =  if_samefringe_2_in_3_gg1(x7)
IF_SAMEFRINGE_2_IN_2_GG6(x1, x2, x3, x4, x5, x6)  =  IF_SAMEFRINGE_2_IN_2_GG2(x5, x6)
IF_SAMEFRINGE_2_IN_3_GG7(x1, x2, x3, x4, x5, x6, x7)  =  IF_SAMEFRINGE_2_IN_3_GG1(x7)
SAMEFRINGE_2_IN_GG2(x1, x2)  =  SAMEFRINGE_2_IN_GG2(x1, x2)
IF_SAMEFRINGE_2_IN_1_GG5(x1, x2, x3, x4, x5)  =  IF_SAMEFRINGE_2_IN_1_GG3(x3, x4, x5)
GOPHER_2_IN_GA2(x1, x2)  =  GOPHER_2_IN_GA1(x1)
IF_GOPHER_2_IN_1_GA5(x1, x2, x3, x4, x5)  =  IF_GOPHER_2_IN_1_GA1(x5)

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

↳ PROLOG
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
PiDP
          ↳ DependencyGraphProof

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

SAMEFRINGE_2_IN_GG2(cons_22(U, V), cons_22(X, Y)) -> IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
SAMEFRINGE_2_IN_GG2(cons_22(U, V), cons_22(X, Y)) -> GOPHER_2_IN_GA2(cons_22(U, V), cons_22(U1, V1))
GOPHER_2_IN_GA2(cons_22(cons_22(U, V), W), X) -> IF_GOPHER_2_IN_1_GA5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
GOPHER_2_IN_GA2(cons_22(cons_22(U, V), W), X) -> GOPHER_2_IN_GA2(cons_22(U, cons_22(V, W)), X)
IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> GOPHER_2_IN_GA2(cons_22(X, Y), cons_22(X1, Y1))
IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> IF_SAMEFRINGE_2_IN_3_GG7(U, V, X, Y, V1, Y1, samefringe_2_in_gg2(V1, Y1))
IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> SAMEFRINGE_2_IN_GG2(V1, Y1)

The TRS R consists of the following rules:

samefringe_2_in_gg2(nil_0, nil_0) -> samefringe_2_out_gg2(nil_0, nil_0)
samefringe_2_in_gg2(cons_22(U, V), cons_22(X, Y)) -> if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
gopher_2_in_ga2(nil_0, nil_0) -> gopher_2_out_ga2(nil_0, nil_0)
gopher_2_in_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y)) -> gopher_2_out_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y))
gopher_2_in_ga2(cons_22(cons_22(U, V), W), X) -> if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_out_ga2(cons_22(U, cons_22(V, W)), X)) -> gopher_2_out_ga2(cons_22(cons_22(U, V), W), X)
if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_in_gg2(V1, Y1))
if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_out_gg2(V1, Y1)) -> samefringe_2_out_gg2(cons_22(U, V), cons_22(X, Y))

The argument filtering Pi contains the following mapping:
samefringe_2_in_gg2(x1, x2)  =  samefringe_2_in_gg2(x1, x2)
nil_0  =  nil_0
cons_22(x1, x2)  =  cons_22(x1, x2)
samefringe_2_out_gg2(x1, x2)  =  samefringe_2_out_gg
if_samefringe_2_in_1_gg5(x1, x2, x3, x4, x5)  =  if_samefringe_2_in_1_gg3(x3, x4, x5)
gopher_2_in_ga2(x1, x2)  =  gopher_2_in_ga1(x1)
gopher_2_out_ga2(x1, x2)  =  gopher_2_out_ga1(x2)
if_gopher_2_in_1_ga5(x1, x2, x3, x4, x5)  =  if_gopher_2_in_1_ga1(x5)
if_samefringe_2_in_2_gg6(x1, x2, x3, x4, x5, x6)  =  if_samefringe_2_in_2_gg2(x5, x6)
if_samefringe_2_in_3_gg7(x1, x2, x3, x4, x5, x6, x7)  =  if_samefringe_2_in_3_gg1(x7)
IF_SAMEFRINGE_2_IN_2_GG6(x1, x2, x3, x4, x5, x6)  =  IF_SAMEFRINGE_2_IN_2_GG2(x5, x6)
IF_SAMEFRINGE_2_IN_3_GG7(x1, x2, x3, x4, x5, x6, x7)  =  IF_SAMEFRINGE_2_IN_3_GG1(x7)
SAMEFRINGE_2_IN_GG2(x1, x2)  =  SAMEFRINGE_2_IN_GG2(x1, x2)
IF_SAMEFRINGE_2_IN_1_GG5(x1, x2, x3, x4, x5)  =  IF_SAMEFRINGE_2_IN_1_GG3(x3, x4, x5)
GOPHER_2_IN_GA2(x1, x2)  =  GOPHER_2_IN_GA1(x1)
IF_GOPHER_2_IN_1_GA5(x1, x2, x3, x4, x5)  =  IF_GOPHER_2_IN_1_GA1(x5)

We have to consider all (P,R,Pi)-chains
The approximation of the Dependency Graph contains 2 SCCs with 4 less nodes.

↳ PROLOG
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
        ↳ PiDP
          ↳ DependencyGraphProof
            ↳ AND
PiDP
                ↳ UsableRulesProof
              ↳ PiDP

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

GOPHER_2_IN_GA2(cons_22(cons_22(U, V), W), X) -> GOPHER_2_IN_GA2(cons_22(U, cons_22(V, W)), X)

The TRS R consists of the following rules:

samefringe_2_in_gg2(nil_0, nil_0) -> samefringe_2_out_gg2(nil_0, nil_0)
samefringe_2_in_gg2(cons_22(U, V), cons_22(X, Y)) -> if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
gopher_2_in_ga2(nil_0, nil_0) -> gopher_2_out_ga2(nil_0, nil_0)
gopher_2_in_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y)) -> gopher_2_out_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y))
gopher_2_in_ga2(cons_22(cons_22(U, V), W), X) -> if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_out_ga2(cons_22(U, cons_22(V, W)), X)) -> gopher_2_out_ga2(cons_22(cons_22(U, V), W), X)
if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_in_gg2(V1, Y1))
if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_out_gg2(V1, Y1)) -> samefringe_2_out_gg2(cons_22(U, V), cons_22(X, Y))

The argument filtering Pi contains the following mapping:
samefringe_2_in_gg2(x1, x2)  =  samefringe_2_in_gg2(x1, x2)
nil_0  =  nil_0
cons_22(x1, x2)  =  cons_22(x1, x2)
samefringe_2_out_gg2(x1, x2)  =  samefringe_2_out_gg
if_samefringe_2_in_1_gg5(x1, x2, x3, x4, x5)  =  if_samefringe_2_in_1_gg3(x3, x4, x5)
gopher_2_in_ga2(x1, x2)  =  gopher_2_in_ga1(x1)
gopher_2_out_ga2(x1, x2)  =  gopher_2_out_ga1(x2)
if_gopher_2_in_1_ga5(x1, x2, x3, x4, x5)  =  if_gopher_2_in_1_ga1(x5)
if_samefringe_2_in_2_gg6(x1, x2, x3, x4, x5, x6)  =  if_samefringe_2_in_2_gg2(x5, x6)
if_samefringe_2_in_3_gg7(x1, x2, x3, x4, x5, x6, x7)  =  if_samefringe_2_in_3_gg1(x7)
GOPHER_2_IN_GA2(x1, x2)  =  GOPHER_2_IN_GA1(x1)

We have to consider all (P,R,Pi)-chains
For (infinitary) constructor rewriting we can delete all non-usable rules from R.

↳ PROLOG
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
        ↳ PiDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ PiDP
                ↳ UsableRulesProof
PiDP
                    ↳ PiDPToQDPProof
              ↳ PiDP

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

GOPHER_2_IN_GA2(cons_22(cons_22(U, V), W), X) -> GOPHER_2_IN_GA2(cons_22(U, cons_22(V, W)), X)

R is empty.
The argument filtering Pi contains the following mapping:
cons_22(x1, x2)  =  cons_22(x1, x2)
GOPHER_2_IN_GA2(x1, x2)  =  GOPHER_2_IN_GA1(x1)

We have to consider all (P,R,Pi)-chains
Transforming (infinitary) constructor rewriting Pi-DP problem into ordinary QDP problem by application of Pi.

↳ PROLOG
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
        ↳ PiDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ PiDP
                ↳ UsableRulesProof
                  ↳ PiDP
                    ↳ PiDPToQDPProof
QDP
                        ↳ QDPSizeChangeProof
              ↳ PiDP

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

GOPHER_2_IN_GA1(cons_22(cons_22(U, V), W)) -> GOPHER_2_IN_GA1(cons_22(U, cons_22(V, W)))

R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
The head symbols of this DP problem are {GOPHER_2_IN_GA1}.
We used the following order and afs together with the size-change analysis to show that there are no infinite chains for this DP problem.

Order:Homeomorphic Embedding Order

AFS:
cons_22(x1, x2)  =  cons_21(x1)

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

We oriented the following set of usable rules. none


↳ PROLOG
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
        ↳ PiDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ PiDP
PiDP
                ↳ UsableRulesProof

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

SAMEFRINGE_2_IN_GG2(cons_22(U, V), cons_22(X, Y)) -> IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> SAMEFRINGE_2_IN_GG2(V1, Y1)

The TRS R consists of the following rules:

samefringe_2_in_gg2(nil_0, nil_0) -> samefringe_2_out_gg2(nil_0, nil_0)
samefringe_2_in_gg2(cons_22(U, V), cons_22(X, Y)) -> if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
gopher_2_in_ga2(nil_0, nil_0) -> gopher_2_out_ga2(nil_0, nil_0)
gopher_2_in_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y)) -> gopher_2_out_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y))
gopher_2_in_ga2(cons_22(cons_22(U, V), W), X) -> if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_out_ga2(cons_22(U, cons_22(V, W)), X)) -> gopher_2_out_ga2(cons_22(cons_22(U, V), W), X)
if_samefringe_2_in_1_gg5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
if_samefringe_2_in_2_gg6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_in_gg2(V1, Y1))
if_samefringe_2_in_3_gg7(U, V, X, Y, V1, Y1, samefringe_2_out_gg2(V1, Y1)) -> samefringe_2_out_gg2(cons_22(U, V), cons_22(X, Y))

The argument filtering Pi contains the following mapping:
samefringe_2_in_gg2(x1, x2)  =  samefringe_2_in_gg2(x1, x2)
nil_0  =  nil_0
cons_22(x1, x2)  =  cons_22(x1, x2)
samefringe_2_out_gg2(x1, x2)  =  samefringe_2_out_gg
if_samefringe_2_in_1_gg5(x1, x2, x3, x4, x5)  =  if_samefringe_2_in_1_gg3(x3, x4, x5)
gopher_2_in_ga2(x1, x2)  =  gopher_2_in_ga1(x1)
gopher_2_out_ga2(x1, x2)  =  gopher_2_out_ga1(x2)
if_gopher_2_in_1_ga5(x1, x2, x3, x4, x5)  =  if_gopher_2_in_1_ga1(x5)
if_samefringe_2_in_2_gg6(x1, x2, x3, x4, x5, x6)  =  if_samefringe_2_in_2_gg2(x5, x6)
if_samefringe_2_in_3_gg7(x1, x2, x3, x4, x5, x6, x7)  =  if_samefringe_2_in_3_gg1(x7)
IF_SAMEFRINGE_2_IN_2_GG6(x1, x2, x3, x4, x5, x6)  =  IF_SAMEFRINGE_2_IN_2_GG2(x5, x6)
SAMEFRINGE_2_IN_GG2(x1, x2)  =  SAMEFRINGE_2_IN_GG2(x1, x2)
IF_SAMEFRINGE_2_IN_1_GG5(x1, x2, x3, x4, x5)  =  IF_SAMEFRINGE_2_IN_1_GG3(x3, x4, x5)

We have to consider all (P,R,Pi)-chains
For (infinitary) constructor rewriting we can delete all non-usable rules from R.

↳ PROLOG
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
        ↳ PiDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ PiDP
              ↳ PiDP
                ↳ UsableRulesProof
PiDP
                    ↳ PiDPToQDPProof

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

SAMEFRINGE_2_IN_GG2(cons_22(U, V), cons_22(X, Y)) -> IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_in_ga2(cons_22(U, V), cons_22(U1, V1)))
IF_SAMEFRINGE_2_IN_1_GG5(U, V, X, Y, gopher_2_out_ga2(cons_22(U, V), cons_22(U1, V1))) -> IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_in_ga2(cons_22(X, Y), cons_22(X1, Y1)))
IF_SAMEFRINGE_2_IN_2_GG6(U, V, X, Y, V1, gopher_2_out_ga2(cons_22(X, Y), cons_22(X1, Y1))) -> SAMEFRINGE_2_IN_GG2(V1, Y1)

The TRS R consists of the following rules:

gopher_2_in_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y)) -> gopher_2_out_ga2(cons_22(nil_0, Y), cons_22(nil_0, Y))
gopher_2_in_ga2(cons_22(cons_22(U, V), W), X) -> if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_in_ga2(cons_22(U, cons_22(V, W)), X))
if_gopher_2_in_1_ga5(U, V, W, X, gopher_2_out_ga2(cons_22(U, cons_22(V, W)), X)) -> gopher_2_out_ga2(cons_22(cons_22(U, V), W), X)

The argument filtering Pi contains the following mapping:
nil_0  =  nil_0
cons_22(x1, x2)  =  cons_22(x1, x2)
gopher_2_in_ga2(x1, x2)  =  gopher_2_in_ga1(x1)
gopher_2_out_ga2(x1, x2)  =  gopher_2_out_ga1(x2)
if_gopher_2_in_1_ga5(x1, x2, x3, x4, x5)  =  if_gopher_2_in_1_ga1(x5)
IF_SAMEFRINGE_2_IN_2_GG6(x1, x2, x3, x4, x5, x6)  =  IF_SAMEFRINGE_2_IN_2_GG2(x5, x6)
SAMEFRINGE_2_IN_GG2(x1, x2)  =  SAMEFRINGE_2_IN_GG2(x1, x2)
IF_SAMEFRINGE_2_IN_1_GG5(x1, x2, x3, x4, x5)  =  IF_SAMEFRINGE_2_IN_1_GG3(x3, x4, x5)

We have to consider all (P,R,Pi)-chains
Transforming (infinitary) constructor rewriting Pi-DP problem into ordinary QDP problem by application of Pi.

↳ PROLOG
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
        ↳ PiDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ PiDP
              ↳ PiDP
                ↳ UsableRulesProof
                  ↳ PiDP
                    ↳ PiDPToQDPProof
QDP
                        ↳ QDPSizeChangeProof

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

SAMEFRINGE_2_IN_GG2(cons_22(U, V), cons_22(X, Y)) -> IF_SAMEFRINGE_2_IN_1_GG3(X, Y, gopher_2_in_ga1(cons_22(U, V)))
IF_SAMEFRINGE_2_IN_1_GG3(X, Y, gopher_2_out_ga1(cons_22(U1, V1))) -> IF_SAMEFRINGE_2_IN_2_GG2(V1, gopher_2_in_ga1(cons_22(X, Y)))
IF_SAMEFRINGE_2_IN_2_GG2(V1, gopher_2_out_ga1(cons_22(X1, Y1))) -> SAMEFRINGE_2_IN_GG2(V1, Y1)

The TRS R consists of the following rules:

gopher_2_in_ga1(cons_22(nil_0, Y)) -> gopher_2_out_ga1(cons_22(nil_0, Y))
gopher_2_in_ga1(cons_22(cons_22(U, V), W)) -> if_gopher_2_in_1_ga1(gopher_2_in_ga1(cons_22(U, cons_22(V, W))))
if_gopher_2_in_1_ga1(gopher_2_out_ga1(X)) -> gopher_2_out_ga1(X)

The set Q consists of the following terms:

gopher_2_in_ga1(x0)
if_gopher_2_in_1_ga1(x0)

We have to consider all (P,Q,R)-chains.
The head symbols of this DP problem are {IF_SAMEFRINGE_2_IN_1_GG3, SAMEFRINGE_2_IN_GG2, IF_SAMEFRINGE_2_IN_2_GG2}.
We used the following order together with the size-change analysis to show that there are no infinite chains for this DP problem.

Order:Polynomial interpretation:


POL(nil_0) = 0   
POL(if_gopher_2_in_1_ga1(x1)) = x1   
POL(gopher_2_out_ga1(x1)) = x1   
POL(gopher_2_in_ga1(x1)) = x1   
POL(cons_22(x1, x2)) = 1 + x1 + x2   

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

We oriented the following set of usable rules.


if_gopher_2_in_1_ga1(gopher_2_out_ga1(X)) -> gopher_2_out_ga1(X)
gopher_2_in_ga1(cons_22(nil_0, Y)) -> gopher_2_out_ga1(cons_22(nil_0, Y))
gopher_2_in_ga1(cons_22(cons_22(U, V), W)) -> if_gopher_2_in_1_ga1(gopher_2_in_ga1(cons_22(U, cons_22(V, W))))