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(.(X, L), Z) :- ','(perm(L, Y), insert(X, Y, Z)).
insert(X, [], .(X, [])).
insert(X, L, .(X, L)).
insert(X, .(H, L1), .(H, L2)) :- insert(X, L1, L2).
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)
insert_in: (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(.(X, L), Z) → U1_ga(X, L, Z, perm_in_ga(L, Y))
U1_ga(X, L, Z, perm_out_ga(L, Y)) → U2_ga(X, L, Z, insert_in_gga(X, Y, Z))
insert_in_gga(X, [], .(X, [])) → insert_out_gga(X, [], .(X, []))
insert_in_gga(X, L, .(X, L)) → insert_out_gga(X, L, .(X, L))
insert_in_gga(X, .(H, L1), .(H, L2)) → U3_gga(X, H, L1, L2, insert_in_gga(X, L1, L2))
U3_gga(X, H, L1, L2, insert_out_gga(X, L1, L2)) → insert_out_gga(X, .(H, L1), .(H, L2))
U2_ga(X, L, Z, insert_out_gga(X, Y, Z)) → perm_out_ga(.(X, L), Z)
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)
.(x1, x2) = .(x1, x2)
U1_ga(x1, x2, x3, x4) = U1_ga(x1, x4)
U2_ga(x1, x2, x3, x4) = U2_ga(x4)
insert_in_gga(x1, x2, x3) = insert_in_gga(x1, x2)
insert_out_gga(x1, x2, x3) = insert_out_gga(x3)
U3_gga(x1, x2, x3, x4, x5) = U3_gga(x2, x5)
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(.(X, L), Z) → U1_ga(X, L, Z, perm_in_ga(L, Y))
U1_ga(X, L, Z, perm_out_ga(L, Y)) → U2_ga(X, L, Z, insert_in_gga(X, Y, Z))
insert_in_gga(X, [], .(X, [])) → insert_out_gga(X, [], .(X, []))
insert_in_gga(X, L, .(X, L)) → insert_out_gga(X, L, .(X, L))
insert_in_gga(X, .(H, L1), .(H, L2)) → U3_gga(X, H, L1, L2, insert_in_gga(X, L1, L2))
U3_gga(X, H, L1, L2, insert_out_gga(X, L1, L2)) → insert_out_gga(X, .(H, L1), .(H, L2))
U2_ga(X, L, Z, insert_out_gga(X, Y, Z)) → perm_out_ga(.(X, L), Z)
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)
.(x1, x2) = .(x1, x2)
U1_ga(x1, x2, x3, x4) = U1_ga(x1, x4)
U2_ga(x1, x2, x3, x4) = U2_ga(x4)
insert_in_gga(x1, x2, x3) = insert_in_gga(x1, x2)
insert_out_gga(x1, x2, x3) = insert_out_gga(x3)
U3_gga(x1, x2, x3, x4, x5) = U3_gga(x2, x5)
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(.(X, L), Z) → U1_GA(X, L, Z, perm_in_ga(L, Y))
PERM_IN_GA(.(X, L), Z) → PERM_IN_GA(L, Y)
U1_GA(X, L, Z, perm_out_ga(L, Y)) → U2_GA(X, L, Z, insert_in_gga(X, Y, Z))
U1_GA(X, L, Z, perm_out_ga(L, Y)) → INSERT_IN_GGA(X, Y, Z)
INSERT_IN_GGA(X, .(H, L1), .(H, L2)) → U3_GGA(X, H, L1, L2, insert_in_gga(X, L1, L2))
INSERT_IN_GGA(X, .(H, L1), .(H, L2)) → INSERT_IN_GGA(X, L1, L2)
The TRS R consists of the following rules:
perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(.(X, L), Z) → U1_ga(X, L, Z, perm_in_ga(L, Y))
U1_ga(X, L, Z, perm_out_ga(L, Y)) → U2_ga(X, L, Z, insert_in_gga(X, Y, Z))
insert_in_gga(X, [], .(X, [])) → insert_out_gga(X, [], .(X, []))
insert_in_gga(X, L, .(X, L)) → insert_out_gga(X, L, .(X, L))
insert_in_gga(X, .(H, L1), .(H, L2)) → U3_gga(X, H, L1, L2, insert_in_gga(X, L1, L2))
U3_gga(X, H, L1, L2, insert_out_gga(X, L1, L2)) → insert_out_gga(X, .(H, L1), .(H, L2))
U2_ga(X, L, Z, insert_out_gga(X, Y, Z)) → perm_out_ga(.(X, L), Z)
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)
.(x1, x2) = .(x1, x2)
U1_ga(x1, x2, x3, x4) = U1_ga(x1, x4)
U2_ga(x1, x2, x3, x4) = U2_ga(x4)
insert_in_gga(x1, x2, x3) = insert_in_gga(x1, x2)
insert_out_gga(x1, x2, x3) = insert_out_gga(x3)
U3_gga(x1, x2, x3, x4, x5) = U3_gga(x2, x5)
U3_GGA(x1, x2, x3, x4, x5) = U3_GGA(x2, x5)
INSERT_IN_GGA(x1, x2, x3) = INSERT_IN_GGA(x1, x2)
U2_GA(x1, x2, x3, x4) = U2_GA(x4)
U1_GA(x1, x2, x3, x4) = U1_GA(x1, 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(.(X, L), Z) → U1_GA(X, L, Z, perm_in_ga(L, Y))
PERM_IN_GA(.(X, L), Z) → PERM_IN_GA(L, Y)
U1_GA(X, L, Z, perm_out_ga(L, Y)) → U2_GA(X, L, Z, insert_in_gga(X, Y, Z))
U1_GA(X, L, Z, perm_out_ga(L, Y)) → INSERT_IN_GGA(X, Y, Z)
INSERT_IN_GGA(X, .(H, L1), .(H, L2)) → U3_GGA(X, H, L1, L2, insert_in_gga(X, L1, L2))
INSERT_IN_GGA(X, .(H, L1), .(H, L2)) → INSERT_IN_GGA(X, L1, L2)
The TRS R consists of the following rules:
perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(.(X, L), Z) → U1_ga(X, L, Z, perm_in_ga(L, Y))
U1_ga(X, L, Z, perm_out_ga(L, Y)) → U2_ga(X, L, Z, insert_in_gga(X, Y, Z))
insert_in_gga(X, [], .(X, [])) → insert_out_gga(X, [], .(X, []))
insert_in_gga(X, L, .(X, L)) → insert_out_gga(X, L, .(X, L))
insert_in_gga(X, .(H, L1), .(H, L2)) → U3_gga(X, H, L1, L2, insert_in_gga(X, L1, L2))
U3_gga(X, H, L1, L2, insert_out_gga(X, L1, L2)) → insert_out_gga(X, .(H, L1), .(H, L2))
U2_ga(X, L, Z, insert_out_gga(X, Y, Z)) → perm_out_ga(.(X, L), Z)
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)
.(x1, x2) = .(x1, x2)
U1_ga(x1, x2, x3, x4) = U1_ga(x1, x4)
U2_ga(x1, x2, x3, x4) = U2_ga(x4)
insert_in_gga(x1, x2, x3) = insert_in_gga(x1, x2)
insert_out_gga(x1, x2, x3) = insert_out_gga(x3)
U3_gga(x1, x2, x3, x4, x5) = U3_gga(x2, x5)
U3_GGA(x1, x2, x3, x4, x5) = U3_GGA(x2, x5)
INSERT_IN_GGA(x1, x2, x3) = INSERT_IN_GGA(x1, x2)
U2_GA(x1, x2, x3, x4) = U2_GA(x4)
U1_GA(x1, x2, x3, x4) = U1_GA(x1, 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 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:
INSERT_IN_GGA(X, .(H, L1), .(H, L2)) → INSERT_IN_GGA(X, L1, L2)
The TRS R consists of the following rules:
perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(.(X, L), Z) → U1_ga(X, L, Z, perm_in_ga(L, Y))
U1_ga(X, L, Z, perm_out_ga(L, Y)) → U2_ga(X, L, Z, insert_in_gga(X, Y, Z))
insert_in_gga(X, [], .(X, [])) → insert_out_gga(X, [], .(X, []))
insert_in_gga(X, L, .(X, L)) → insert_out_gga(X, L, .(X, L))
insert_in_gga(X, .(H, L1), .(H, L2)) → U3_gga(X, H, L1, L2, insert_in_gga(X, L1, L2))
U3_gga(X, H, L1, L2, insert_out_gga(X, L1, L2)) → insert_out_gga(X, .(H, L1), .(H, L2))
U2_ga(X, L, Z, insert_out_gga(X, Y, Z)) → perm_out_ga(.(X, L), Z)
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)
.(x1, x2) = .(x1, x2)
U1_ga(x1, x2, x3, x4) = U1_ga(x1, x4)
U2_ga(x1, x2, x3, x4) = U2_ga(x4)
insert_in_gga(x1, x2, x3) = insert_in_gga(x1, x2)
insert_out_gga(x1, x2, x3) = insert_out_gga(x3)
U3_gga(x1, x2, x3, x4, x5) = U3_gga(x2, x5)
INSERT_IN_GGA(x1, x2, x3) = INSERT_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
Pi DP problem:
The TRS P consists of the following rules:
INSERT_IN_GGA(X, .(H, L1), .(H, L2)) → INSERT_IN_GGA(X, L1, L2)
R is empty.
The argument filtering Pi contains the following mapping:
.(x1, x2) = .(x1, x2)
INSERT_IN_GGA(x1, x2, x3) = INSERT_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
Q DP problem:
The TRS P consists of the following rules:
INSERT_IN_GGA(X, .(H, L1)) → INSERT_IN_GGA(X, L1)
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:
- INSERT_IN_GGA(X, .(H, L1)) → INSERT_IN_GGA(X, L1)
The graph contains the following edges 1 >= 1, 2 > 2
↳ Prolog
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
↳ AND
↳ PiDP
↳ PiDP
↳ UsableRulesProof
Pi DP problem:
The TRS P consists of the following rules:
PERM_IN_GA(.(X, L), Z) → PERM_IN_GA(L, Y)
The TRS R consists of the following rules:
perm_in_ga([], []) → perm_out_ga([], [])
perm_in_ga(.(X, L), Z) → U1_ga(X, L, Z, perm_in_ga(L, Y))
U1_ga(X, L, Z, perm_out_ga(L, Y)) → U2_ga(X, L, Z, insert_in_gga(X, Y, Z))
insert_in_gga(X, [], .(X, [])) → insert_out_gga(X, [], .(X, []))
insert_in_gga(X, L, .(X, L)) → insert_out_gga(X, L, .(X, L))
insert_in_gga(X, .(H, L1), .(H, L2)) → U3_gga(X, H, L1, L2, insert_in_gga(X, L1, L2))
U3_gga(X, H, L1, L2, insert_out_gga(X, L1, L2)) → insert_out_gga(X, .(H, L1), .(H, L2))
U2_ga(X, L, Z, insert_out_gga(X, Y, Z)) → perm_out_ga(.(X, L), Z)
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)
.(x1, x2) = .(x1, x2)
U1_ga(x1, x2, x3, x4) = U1_ga(x1, x4)
U2_ga(x1, x2, x3, x4) = U2_ga(x4)
insert_in_gga(x1, x2, x3) = insert_in_gga(x1, x2)
insert_out_gga(x1, x2, x3) = insert_out_gga(x3)
U3_gga(x1, x2, x3, x4, x5) = U3_gga(x2, x5)
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
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
Pi DP problem:
The TRS P consists of the following rules:
PERM_IN_GA(.(X, L), Z) → PERM_IN_GA(L, Y)
R is empty.
The argument filtering Pi contains the following mapping:
.(x1, x2) = .(x1, x2)
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
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
↳ QDP
↳ QDPSizeChangeProof
Q DP problem:
The TRS P consists of the following rules:
PERM_IN_GA(.(X, L)) → PERM_IN_GA(L)
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:
- PERM_IN_GA(.(X, L)) → PERM_IN_GA(L)
The graph contains the following edges 1 > 1