Left Termination of the query pattern perm_in_2(g, a) w.r.t. the given Prolog program could successfully be proven:



Prolog
  ↳ PrologToPiTRSProof

Clauses:

perm([], []).
perm(Xs, .(X, Ys)) :- ','(app(X1s, .(X, X2s), Xs), ','(app(X1s, X2s, Zs), perm(Zs, Ys))).
app([], X, X).
app(.(X, Xs), Ys, .(X, Zs)) :- app(Xs, Ys, Zs).

Queries:

perm(g,a).

We use the technique of [30]. With regard to the inferred argument filtering the predicates were used in the following modes:
perm_in: (b,f)
app_in: (f,f,b) (b,b,f)
Transforming Prolog into the following Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:

perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(Xs, .(X, Ys)) → U1_ga(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
app_in_aag([], X, X) → app_out_aag([], X, X)
app_in_aag(.(X, Xs), Ys, .(X, Zs)) → U4_aag(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
U4_aag(X, Xs, Ys, Zs, app_out_aag(Xs, Ys, Zs)) → app_out_aag(.(X, Xs), Ys, .(X, Zs))
U1_ga(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_ga(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
app_in_gga([], X, X) → app_out_gga([], X, X)
app_in_gga(.(X, Xs), Ys, .(X, Zs)) → U4_gga(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
U4_gga(X, Xs, Ys, Zs, app_out_gga(Xs, Ys, Zs)) → app_out_gga(.(X, Xs), Ys, .(X, Zs))
U2_ga(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_ga(Xs, X, Ys, perm_in_ga(Zs, Ys))
U3_ga(Xs, X, Ys, perm_out_ga(Zs, Ys)) → perm_out_ga(Xs, .(X, Ys))

The argument filtering Pi contains the following mapping:
perm_in_ga(x1, x2)  =  perm_in_ga(x1)
[]  =  []
perm_out_ga(x1, x2)  =  perm_out_ga(x2)
U1_ga(x1, x2, x3, x4)  =  U1_ga(x4)
app_in_aag(x1, x2, x3)  =  app_in_aag(x3)
.(x1, x2)  =  .(x2)
app_out_aag(x1, x2, x3)  =  app_out_aag(x1, x2)
U4_aag(x1, x2, x3, x4, x5)  =  U4_aag(x5)
U2_ga(x1, x2, x3, x4)  =  U2_ga(x4)
app_in_gga(x1, x2, x3)  =  app_in_gga(x1, x2)
app_out_gga(x1, x2, x3)  =  app_out_gga(x3)
U4_gga(x1, x2, x3, x4, x5)  =  U4_gga(x5)
U3_ga(x1, x2, x3, x4)  =  U3_ga(x4)

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:

perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(Xs, .(X, Ys)) → U1_ga(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
app_in_aag([], X, X) → app_out_aag([], X, X)
app_in_aag(.(X, Xs), Ys, .(X, Zs)) → U4_aag(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
U4_aag(X, Xs, Ys, Zs, app_out_aag(Xs, Ys, Zs)) → app_out_aag(.(X, Xs), Ys, .(X, Zs))
U1_ga(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_ga(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
app_in_gga([], X, X) → app_out_gga([], X, X)
app_in_gga(.(X, Xs), Ys, .(X, Zs)) → U4_gga(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
U4_gga(X, Xs, Ys, Zs, app_out_gga(Xs, Ys, Zs)) → app_out_gga(.(X, Xs), Ys, .(X, Zs))
U2_ga(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_ga(Xs, X, Ys, perm_in_ga(Zs, Ys))
U3_ga(Xs, X, Ys, perm_out_ga(Zs, Ys)) → perm_out_ga(Xs, .(X, Ys))

The argument filtering Pi contains the following mapping:
perm_in_ga(x1, x2)  =  perm_in_ga(x1)
[]  =  []
perm_out_ga(x1, x2)  =  perm_out_ga(x2)
U1_ga(x1, x2, x3, x4)  =  U1_ga(x4)
app_in_aag(x1, x2, x3)  =  app_in_aag(x3)
.(x1, x2)  =  .(x2)
app_out_aag(x1, x2, x3)  =  app_out_aag(x1, x2)
U4_aag(x1, x2, x3, x4, x5)  =  U4_aag(x5)
U2_ga(x1, x2, x3, x4)  =  U2_ga(x4)
app_in_gga(x1, x2, x3)  =  app_in_gga(x1, x2)
app_out_gga(x1, x2, x3)  =  app_out_gga(x3)
U4_gga(x1, x2, x3, x4, x5)  =  U4_gga(x5)
U3_ga(x1, x2, x3, x4)  =  U3_ga(x4)


Using Dependency Pairs [1,30] we result in the following initial DP problem:
Pi DP problem:
The TRS P consists of the following rules:

PERM_IN_GA(Xs, .(X, Ys)) → U1_GA(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
PERM_IN_GA(Xs, .(X, Ys)) → APP_IN_AAG(X1s, .(X, X2s), Xs)
APP_IN_AAG(.(X, Xs), Ys, .(X, Zs)) → U4_AAG(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
APP_IN_AAG(.(X, Xs), Ys, .(X, Zs)) → APP_IN_AAG(Xs, Ys, Zs)
U1_GA(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_GA(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
U1_GA(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → APP_IN_GGA(X1s, X2s, Zs)
APP_IN_GGA(.(X, Xs), Ys, .(X, Zs)) → U4_GGA(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
APP_IN_GGA(.(X, Xs), Ys, .(X, Zs)) → APP_IN_GGA(Xs, Ys, Zs)
U2_GA(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_GA(Xs, X, Ys, perm_in_ga(Zs, Ys))
U2_GA(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → PERM_IN_GA(Zs, Ys)

The TRS R consists of the following rules:

perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(Xs, .(X, Ys)) → U1_ga(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
app_in_aag([], X, X) → app_out_aag([], X, X)
app_in_aag(.(X, Xs), Ys, .(X, Zs)) → U4_aag(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
U4_aag(X, Xs, Ys, Zs, app_out_aag(Xs, Ys, Zs)) → app_out_aag(.(X, Xs), Ys, .(X, Zs))
U1_ga(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_ga(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
app_in_gga([], X, X) → app_out_gga([], X, X)
app_in_gga(.(X, Xs), Ys, .(X, Zs)) → U4_gga(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
U4_gga(X, Xs, Ys, Zs, app_out_gga(Xs, Ys, Zs)) → app_out_gga(.(X, Xs), Ys, .(X, Zs))
U2_ga(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_ga(Xs, X, Ys, perm_in_ga(Zs, Ys))
U3_ga(Xs, X, Ys, perm_out_ga(Zs, Ys)) → perm_out_ga(Xs, .(X, Ys))

The argument filtering Pi contains the following mapping:
perm_in_ga(x1, x2)  =  perm_in_ga(x1)
[]  =  []
perm_out_ga(x1, x2)  =  perm_out_ga(x2)
U1_ga(x1, x2, x3, x4)  =  U1_ga(x4)
app_in_aag(x1, x2, x3)  =  app_in_aag(x3)
.(x1, x2)  =  .(x2)
app_out_aag(x1, x2, x3)  =  app_out_aag(x1, x2)
U4_aag(x1, x2, x3, x4, x5)  =  U4_aag(x5)
U2_ga(x1, x2, x3, x4)  =  U2_ga(x4)
app_in_gga(x1, x2, x3)  =  app_in_gga(x1, x2)
app_out_gga(x1, x2, x3)  =  app_out_gga(x3)
U4_gga(x1, x2, x3, x4, x5)  =  U4_gga(x5)
U3_ga(x1, x2, x3, x4)  =  U3_ga(x4)
APP_IN_GGA(x1, x2, x3)  =  APP_IN_GGA(x1, x2)
U4_AAG(x1, x2, x3, x4, x5)  =  U4_AAG(x5)
APP_IN_AAG(x1, x2, x3)  =  APP_IN_AAG(x3)
U4_GGA(x1, x2, x3, x4, x5)  =  U4_GGA(x5)
U3_GA(x1, x2, x3, x4)  =  U3_GA(x4)
U2_GA(x1, x2, x3, x4)  =  U2_GA(x4)
U1_GA(x1, x2, x3, x4)  =  U1_GA(x4)
PERM_IN_GA(x1, x2)  =  PERM_IN_GA(x1)

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:

PERM_IN_GA(Xs, .(X, Ys)) → U1_GA(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
PERM_IN_GA(Xs, .(X, Ys)) → APP_IN_AAG(X1s, .(X, X2s), Xs)
APP_IN_AAG(.(X, Xs), Ys, .(X, Zs)) → U4_AAG(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
APP_IN_AAG(.(X, Xs), Ys, .(X, Zs)) → APP_IN_AAG(Xs, Ys, Zs)
U1_GA(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_GA(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
U1_GA(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → APP_IN_GGA(X1s, X2s, Zs)
APP_IN_GGA(.(X, Xs), Ys, .(X, Zs)) → U4_GGA(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
APP_IN_GGA(.(X, Xs), Ys, .(X, Zs)) → APP_IN_GGA(Xs, Ys, Zs)
U2_GA(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_GA(Xs, X, Ys, perm_in_ga(Zs, Ys))
U2_GA(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → PERM_IN_GA(Zs, Ys)

The TRS R consists of the following rules:

perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(Xs, .(X, Ys)) → U1_ga(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
app_in_aag([], X, X) → app_out_aag([], X, X)
app_in_aag(.(X, Xs), Ys, .(X, Zs)) → U4_aag(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
U4_aag(X, Xs, Ys, Zs, app_out_aag(Xs, Ys, Zs)) → app_out_aag(.(X, Xs), Ys, .(X, Zs))
U1_ga(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_ga(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
app_in_gga([], X, X) → app_out_gga([], X, X)
app_in_gga(.(X, Xs), Ys, .(X, Zs)) → U4_gga(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
U4_gga(X, Xs, Ys, Zs, app_out_gga(Xs, Ys, Zs)) → app_out_gga(.(X, Xs), Ys, .(X, Zs))
U2_ga(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_ga(Xs, X, Ys, perm_in_ga(Zs, Ys))
U3_ga(Xs, X, Ys, perm_out_ga(Zs, Ys)) → perm_out_ga(Xs, .(X, Ys))

The argument filtering Pi contains the following mapping:
perm_in_ga(x1, x2)  =  perm_in_ga(x1)
[]  =  []
perm_out_ga(x1, x2)  =  perm_out_ga(x2)
U1_ga(x1, x2, x3, x4)  =  U1_ga(x4)
app_in_aag(x1, x2, x3)  =  app_in_aag(x3)
.(x1, x2)  =  .(x2)
app_out_aag(x1, x2, x3)  =  app_out_aag(x1, x2)
U4_aag(x1, x2, x3, x4, x5)  =  U4_aag(x5)
U2_ga(x1, x2, x3, x4)  =  U2_ga(x4)
app_in_gga(x1, x2, x3)  =  app_in_gga(x1, x2)
app_out_gga(x1, x2, x3)  =  app_out_gga(x3)
U4_gga(x1, x2, x3, x4, x5)  =  U4_gga(x5)
U3_ga(x1, x2, x3, x4)  =  U3_ga(x4)
APP_IN_GGA(x1, x2, x3)  =  APP_IN_GGA(x1, x2)
U4_AAG(x1, x2, x3, x4, x5)  =  U4_AAG(x5)
APP_IN_AAG(x1, x2, x3)  =  APP_IN_AAG(x3)
U4_GGA(x1, x2, x3, x4, x5)  =  U4_GGA(x5)
U3_GA(x1, x2, x3, x4)  =  U3_GA(x4)
U2_GA(x1, x2, x3, x4)  =  U2_GA(x4)
U1_GA(x1, x2, x3, x4)  =  U1_GA(x4)
PERM_IN_GA(x1, x2)  =  PERM_IN_GA(x1)

We have to consider all (P,R,Pi)-chains
The approximation of the Dependency Graph [30] contains 3 SCCs with 5 less nodes.

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

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

APP_IN_GGA(.(X, Xs), Ys, .(X, Zs)) → APP_IN_GGA(Xs, Ys, Zs)

The TRS R consists of the following rules:

perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(Xs, .(X, Ys)) → U1_ga(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
app_in_aag([], X, X) → app_out_aag([], X, X)
app_in_aag(.(X, Xs), Ys, .(X, Zs)) → U4_aag(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
U4_aag(X, Xs, Ys, Zs, app_out_aag(Xs, Ys, Zs)) → app_out_aag(.(X, Xs), Ys, .(X, Zs))
U1_ga(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_ga(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
app_in_gga([], X, X) → app_out_gga([], X, X)
app_in_gga(.(X, Xs), Ys, .(X, Zs)) → U4_gga(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
U4_gga(X, Xs, Ys, Zs, app_out_gga(Xs, Ys, Zs)) → app_out_gga(.(X, Xs), Ys, .(X, Zs))
U2_ga(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_ga(Xs, X, Ys, perm_in_ga(Zs, Ys))
U3_ga(Xs, X, Ys, perm_out_ga(Zs, Ys)) → perm_out_ga(Xs, .(X, Ys))

The argument filtering Pi contains the following mapping:
perm_in_ga(x1, x2)  =  perm_in_ga(x1)
[]  =  []
perm_out_ga(x1, x2)  =  perm_out_ga(x2)
U1_ga(x1, x2, x3, x4)  =  U1_ga(x4)
app_in_aag(x1, x2, x3)  =  app_in_aag(x3)
.(x1, x2)  =  .(x2)
app_out_aag(x1, x2, x3)  =  app_out_aag(x1, x2)
U4_aag(x1, x2, x3, x4, x5)  =  U4_aag(x5)
U2_ga(x1, x2, x3, x4)  =  U2_ga(x4)
app_in_gga(x1, x2, x3)  =  app_in_gga(x1, x2)
app_out_gga(x1, x2, x3)  =  app_out_gga(x3)
U4_gga(x1, x2, x3, x4, x5)  =  U4_gga(x5)
U3_ga(x1, x2, x3, x4)  =  U3_ga(x4)
APP_IN_GGA(x1, x2, x3)  =  APP_IN_GGA(x1, x2)

We have to consider all (P,R,Pi)-chains
For (infinitary) constructor rewriting [30] we can delete all non-usable rules from R.

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

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

APP_IN_GGA(.(X, Xs), Ys, .(X, Zs)) → APP_IN_GGA(Xs, Ys, Zs)

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

We have to consider all (P,R,Pi)-chains
Transforming (infinitary) constructor rewriting Pi-DP problem [30] into ordinary QDP problem [15] by application of Pi.

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

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

APP_IN_GGA(.(Xs), Ys) → APP_IN_GGA(Xs, Ys)

R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
By using the subterm criterion [20] together with the size-change analysis [32] 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:



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

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

APP_IN_AAG(.(X, Xs), Ys, .(X, Zs)) → APP_IN_AAG(Xs, Ys, Zs)

The TRS R consists of the following rules:

perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(Xs, .(X, Ys)) → U1_ga(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
app_in_aag([], X, X) → app_out_aag([], X, X)
app_in_aag(.(X, Xs), Ys, .(X, Zs)) → U4_aag(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
U4_aag(X, Xs, Ys, Zs, app_out_aag(Xs, Ys, Zs)) → app_out_aag(.(X, Xs), Ys, .(X, Zs))
U1_ga(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_ga(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
app_in_gga([], X, X) → app_out_gga([], X, X)
app_in_gga(.(X, Xs), Ys, .(X, Zs)) → U4_gga(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
U4_gga(X, Xs, Ys, Zs, app_out_gga(Xs, Ys, Zs)) → app_out_gga(.(X, Xs), Ys, .(X, Zs))
U2_ga(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_ga(Xs, X, Ys, perm_in_ga(Zs, Ys))
U3_ga(Xs, X, Ys, perm_out_ga(Zs, Ys)) → perm_out_ga(Xs, .(X, Ys))

The argument filtering Pi contains the following mapping:
perm_in_ga(x1, x2)  =  perm_in_ga(x1)
[]  =  []
perm_out_ga(x1, x2)  =  perm_out_ga(x2)
U1_ga(x1, x2, x3, x4)  =  U1_ga(x4)
app_in_aag(x1, x2, x3)  =  app_in_aag(x3)
.(x1, x2)  =  .(x2)
app_out_aag(x1, x2, x3)  =  app_out_aag(x1, x2)
U4_aag(x1, x2, x3, x4, x5)  =  U4_aag(x5)
U2_ga(x1, x2, x3, x4)  =  U2_ga(x4)
app_in_gga(x1, x2, x3)  =  app_in_gga(x1, x2)
app_out_gga(x1, x2, x3)  =  app_out_gga(x3)
U4_gga(x1, x2, x3, x4, x5)  =  U4_gga(x5)
U3_ga(x1, x2, x3, x4)  =  U3_ga(x4)
APP_IN_AAG(x1, x2, x3)  =  APP_IN_AAG(x3)

We have to consider all (P,R,Pi)-chains
For (infinitary) constructor rewriting [30] we can delete all non-usable rules from R.

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

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

APP_IN_AAG(.(X, Xs), Ys, .(X, Zs)) → APP_IN_AAG(Xs, Ys, Zs)

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

We have to consider all (P,R,Pi)-chains
Transforming (infinitary) constructor rewriting Pi-DP problem [30] into ordinary QDP problem [15] by application of Pi.

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

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

APP_IN_AAG(.(Zs)) → APP_IN_AAG(Zs)

R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
By using the subterm criterion [20] together with the size-change analysis [32] 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:



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

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

U1_GA(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_GA(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
PERM_IN_GA(Xs, .(X, Ys)) → U1_GA(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
U2_GA(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → PERM_IN_GA(Zs, Ys)

The TRS R consists of the following rules:

perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(Xs, .(X, Ys)) → U1_ga(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
app_in_aag([], X, X) → app_out_aag([], X, X)
app_in_aag(.(X, Xs), Ys, .(X, Zs)) → U4_aag(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
U4_aag(X, Xs, Ys, Zs, app_out_aag(Xs, Ys, Zs)) → app_out_aag(.(X, Xs), Ys, .(X, Zs))
U1_ga(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_ga(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
app_in_gga([], X, X) → app_out_gga([], X, X)
app_in_gga(.(X, Xs), Ys, .(X, Zs)) → U4_gga(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
U4_gga(X, Xs, Ys, Zs, app_out_gga(Xs, Ys, Zs)) → app_out_gga(.(X, Xs), Ys, .(X, Zs))
U2_ga(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → U3_ga(Xs, X, Ys, perm_in_ga(Zs, Ys))
U3_ga(Xs, X, Ys, perm_out_ga(Zs, Ys)) → perm_out_ga(Xs, .(X, Ys))

The argument filtering Pi contains the following mapping:
perm_in_ga(x1, x2)  =  perm_in_ga(x1)
[]  =  []
perm_out_ga(x1, x2)  =  perm_out_ga(x2)
U1_ga(x1, x2, x3, x4)  =  U1_ga(x4)
app_in_aag(x1, x2, x3)  =  app_in_aag(x3)
.(x1, x2)  =  .(x2)
app_out_aag(x1, x2, x3)  =  app_out_aag(x1, x2)
U4_aag(x1, x2, x3, x4, x5)  =  U4_aag(x5)
U2_ga(x1, x2, x3, x4)  =  U2_ga(x4)
app_in_gga(x1, x2, x3)  =  app_in_gga(x1, x2)
app_out_gga(x1, x2, x3)  =  app_out_gga(x3)
U4_gga(x1, x2, x3, x4, x5)  =  U4_gga(x5)
U3_ga(x1, x2, x3, x4)  =  U3_ga(x4)
U2_GA(x1, x2, x3, x4)  =  U2_GA(x4)
U1_GA(x1, x2, x3, x4)  =  U1_GA(x4)
PERM_IN_GA(x1, x2)  =  PERM_IN_GA(x1)

We have to consider all (P,R,Pi)-chains
For (infinitary) constructor rewriting [30] we can delete all non-usable rules from R.

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

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

U1_GA(Xs, X, Ys, app_out_aag(X1s, .(X, X2s), Xs)) → U2_GA(Xs, X, Ys, app_in_gga(X1s, X2s, Zs))
PERM_IN_GA(Xs, .(X, Ys)) → U1_GA(Xs, X, Ys, app_in_aag(X1s, .(X, X2s), Xs))
U2_GA(Xs, X, Ys, app_out_gga(X1s, X2s, Zs)) → PERM_IN_GA(Zs, Ys)

The TRS R consists of the following rules:

app_in_gga([], X, X) → app_out_gga([], X, X)
app_in_gga(.(X, Xs), Ys, .(X, Zs)) → U4_gga(X, Xs, Ys, Zs, app_in_gga(Xs, Ys, Zs))
app_in_aag([], X, X) → app_out_aag([], X, X)
app_in_aag(.(X, Xs), Ys, .(X, Zs)) → U4_aag(X, Xs, Ys, Zs, app_in_aag(Xs, Ys, Zs))
U4_gga(X, Xs, Ys, Zs, app_out_gga(Xs, Ys, Zs)) → app_out_gga(.(X, Xs), Ys, .(X, Zs))
U4_aag(X, Xs, Ys, Zs, app_out_aag(Xs, Ys, Zs)) → app_out_aag(.(X, Xs), Ys, .(X, Zs))

The argument filtering Pi contains the following mapping:
[]  =  []
app_in_aag(x1, x2, x3)  =  app_in_aag(x3)
.(x1, x2)  =  .(x2)
app_out_aag(x1, x2, x3)  =  app_out_aag(x1, x2)
U4_aag(x1, x2, x3, x4, x5)  =  U4_aag(x5)
app_in_gga(x1, x2, x3)  =  app_in_gga(x1, x2)
app_out_gga(x1, x2, x3)  =  app_out_gga(x3)
U4_gga(x1, x2, x3, x4, x5)  =  U4_gga(x5)
U2_GA(x1, x2, x3, x4)  =  U2_GA(x4)
U1_GA(x1, x2, x3, x4)  =  U1_GA(x4)
PERM_IN_GA(x1, x2)  =  PERM_IN_GA(x1)

We have to consider all (P,R,Pi)-chains
Transforming (infinitary) constructor rewriting Pi-DP problem [30] into ordinary QDP problem [15] by application of Pi.

↳ Prolog
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
        ↳ PiDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ PiDP
              ↳ PiDP
              ↳ PiDP
                ↳ UsableRulesProof
                  ↳ PiDP
                    ↳ PiDPToQDPProof
QDP
                        ↳ RuleRemovalProof

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

U1_GA(app_out_aag(X1s, .(X2s))) → U2_GA(app_in_gga(X1s, X2s))
U2_GA(app_out_gga(Zs)) → PERM_IN_GA(Zs)
PERM_IN_GA(Xs) → U1_GA(app_in_aag(Xs))

The TRS R consists of the following rules:

app_in_gga([], X) → app_out_gga(X)
app_in_gga(.(Xs), Ys) → U4_gga(app_in_gga(Xs, Ys))
app_in_aag(X) → app_out_aag([], X)
app_in_aag(.(Zs)) → U4_aag(app_in_aag(Zs))
U4_gga(app_out_gga(Zs)) → app_out_gga(.(Zs))
U4_aag(app_out_aag(Xs, Ys)) → app_out_aag(.(Xs), Ys)

The set Q consists of the following terms:

app_in_gga(x0, x1)
app_in_aag(x0)
U4_gga(x0)
U4_aag(x0)

We have to consider all (P,Q,R)-chains.
By using the rule removal processor [15] with the following polynomial ordering [25], at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented.
Strictly oriented dependency pairs:

U1_GA(app_out_aag(X1s, .(X2s))) → U2_GA(app_in_gga(X1s, X2s))


Used ordering: POLO with Polynomial interpretation [25]:

POL(.(x1)) = 1 + x1   
POL(PERM_IN_GA(x1)) = 2·x1   
POL(U1_GA(x1)) = 2·x1   
POL(U2_GA(x1)) = 2·x1   
POL(U4_aag(x1)) = 1 + x1   
POL(U4_gga(x1)) = 1 + x1   
POL([]) = 0   
POL(app_in_aag(x1)) = x1   
POL(app_in_gga(x1, x2)) = x1 + x2   
POL(app_out_aag(x1, x2)) = x1 + x2   
POL(app_out_gga(x1)) = x1   



↳ Prolog
  ↳ PrologToPiTRSProof
    ↳ PiTRS
      ↳ DependencyPairsProof
        ↳ PiDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ PiDP
              ↳ PiDP
              ↳ PiDP
                ↳ UsableRulesProof
                  ↳ PiDP
                    ↳ PiDPToQDPProof
                      ↳ QDP
                        ↳ RuleRemovalProof
QDP
                            ↳ DependencyGraphProof

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

PERM_IN_GA(Xs) → U1_GA(app_in_aag(Xs))
U2_GA(app_out_gga(Zs)) → PERM_IN_GA(Zs)

The TRS R consists of the following rules:

app_in_gga([], X) → app_out_gga(X)
app_in_gga(.(Xs), Ys) → U4_gga(app_in_gga(Xs, Ys))
app_in_aag(X) → app_out_aag([], X)
app_in_aag(.(Zs)) → U4_aag(app_in_aag(Zs))
U4_gga(app_out_gga(Zs)) → app_out_gga(.(Zs))
U4_aag(app_out_aag(Xs, Ys)) → app_out_aag(.(Xs), Ys)

The set Q consists of the following terms:

app_in_gga(x0, x1)
app_in_aag(x0)
U4_gga(x0)
U4_aag(x0)

We have to consider all (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 0 SCCs with 2 less nodes.