Left Termination of the query pattern
rev_in_2(g, a)
w.r.t. the given Prolog program could successfully be proven:
↳ Prolog
↳ PrologToPiTRSProof
Clauses:
rev(LS, RES) :- r1(LS, [], RES).
r1([], RES, RES).
r1(.(X, Xs), Accm, RES) :- r1(Xs, .(X, Accm), RES).
Queries:
rev(g,a).
We use the technique of [30]. With regard to the inferred argument filtering the predicates were used in the following modes:
rev_in: (b,f)
r1_in: (b,b,f)
Transforming Prolog into the following Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
rev_in_ga(LS, RES) → U1_ga(LS, RES, r1_in_gga(LS, [], RES))
r1_in_gga([], RES, RES) → r1_out_gga([], RES, RES)
r1_in_gga(.(X, Xs), Accm, RES) → U2_gga(X, Xs, Accm, RES, r1_in_gga(Xs, .(X, Accm), RES))
U2_gga(X, Xs, Accm, RES, r1_out_gga(Xs, .(X, Accm), RES)) → r1_out_gga(.(X, Xs), Accm, RES)
U1_ga(LS, RES, r1_out_gga(LS, [], RES)) → rev_out_ga(LS, RES)
The argument filtering Pi contains the following mapping:
rev_in_ga(x1, x2) = rev_in_ga(x1)
U1_ga(x1, x2, x3) = U1_ga(x3)
r1_in_gga(x1, x2, x3) = r1_in_gga(x1, x2)
[] = []
r1_out_gga(x1, x2, x3) = r1_out_gga(x3)
.(x1, x2) = .(x1, x2)
U2_gga(x1, x2, x3, x4, x5) = U2_gga(x5)
rev_out_ga(x1, x2) = rev_out_ga(x2)
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:
rev_in_ga(LS, RES) → U1_ga(LS, RES, r1_in_gga(LS, [], RES))
r1_in_gga([], RES, RES) → r1_out_gga([], RES, RES)
r1_in_gga(.(X, Xs), Accm, RES) → U2_gga(X, Xs, Accm, RES, r1_in_gga(Xs, .(X, Accm), RES))
U2_gga(X, Xs, Accm, RES, r1_out_gga(Xs, .(X, Accm), RES)) → r1_out_gga(.(X, Xs), Accm, RES)
U1_ga(LS, RES, r1_out_gga(LS, [], RES)) → rev_out_ga(LS, RES)
The argument filtering Pi contains the following mapping:
rev_in_ga(x1, x2) = rev_in_ga(x1)
U1_ga(x1, x2, x3) = U1_ga(x3)
r1_in_gga(x1, x2, x3) = r1_in_gga(x1, x2)
[] = []
r1_out_gga(x1, x2, x3) = r1_out_gga(x3)
.(x1, x2) = .(x1, x2)
U2_gga(x1, x2, x3, x4, x5) = U2_gga(x5)
rev_out_ga(x1, x2) = rev_out_ga(x2)
Using Dependency Pairs [1,30] we result in the following initial DP problem:
Pi DP problem:
The TRS P consists of the following rules:
REV_IN_GA(LS, RES) → U1_GA(LS, RES, r1_in_gga(LS, [], RES))
REV_IN_GA(LS, RES) → R1_IN_GGA(LS, [], RES)
R1_IN_GGA(.(X, Xs), Accm, RES) → U2_GGA(X, Xs, Accm, RES, r1_in_gga(Xs, .(X, Accm), RES))
R1_IN_GGA(.(X, Xs), Accm, RES) → R1_IN_GGA(Xs, .(X, Accm), RES)
The TRS R consists of the following rules:
rev_in_ga(LS, RES) → U1_ga(LS, RES, r1_in_gga(LS, [], RES))
r1_in_gga([], RES, RES) → r1_out_gga([], RES, RES)
r1_in_gga(.(X, Xs), Accm, RES) → U2_gga(X, Xs, Accm, RES, r1_in_gga(Xs, .(X, Accm), RES))
U2_gga(X, Xs, Accm, RES, r1_out_gga(Xs, .(X, Accm), RES)) → r1_out_gga(.(X, Xs), Accm, RES)
U1_ga(LS, RES, r1_out_gga(LS, [], RES)) → rev_out_ga(LS, RES)
The argument filtering Pi contains the following mapping:
rev_in_ga(x1, x2) = rev_in_ga(x1)
U1_ga(x1, x2, x3) = U1_ga(x3)
r1_in_gga(x1, x2, x3) = r1_in_gga(x1, x2)
[] = []
r1_out_gga(x1, x2, x3) = r1_out_gga(x3)
.(x1, x2) = .(x1, x2)
U2_gga(x1, x2, x3, x4, x5) = U2_gga(x5)
rev_out_ga(x1, x2) = rev_out_ga(x2)
U2_GGA(x1, x2, x3, x4, x5) = U2_GGA(x5)
R1_IN_GGA(x1, x2, x3) = R1_IN_GGA(x1, x2)
REV_IN_GA(x1, x2) = REV_IN_GA(x1)
U1_GA(x1, x2, x3) = U1_GA(x3)
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:
REV_IN_GA(LS, RES) → U1_GA(LS, RES, r1_in_gga(LS, [], RES))
REV_IN_GA(LS, RES) → R1_IN_GGA(LS, [], RES)
R1_IN_GGA(.(X, Xs), Accm, RES) → U2_GGA(X, Xs, Accm, RES, r1_in_gga(Xs, .(X, Accm), RES))
R1_IN_GGA(.(X, Xs), Accm, RES) → R1_IN_GGA(Xs, .(X, Accm), RES)
The TRS R consists of the following rules:
rev_in_ga(LS, RES) → U1_ga(LS, RES, r1_in_gga(LS, [], RES))
r1_in_gga([], RES, RES) → r1_out_gga([], RES, RES)
r1_in_gga(.(X, Xs), Accm, RES) → U2_gga(X, Xs, Accm, RES, r1_in_gga(Xs, .(X, Accm), RES))
U2_gga(X, Xs, Accm, RES, r1_out_gga(Xs, .(X, Accm), RES)) → r1_out_gga(.(X, Xs), Accm, RES)
U1_ga(LS, RES, r1_out_gga(LS, [], RES)) → rev_out_ga(LS, RES)
The argument filtering Pi contains the following mapping:
rev_in_ga(x1, x2) = rev_in_ga(x1)
U1_ga(x1, x2, x3) = U1_ga(x3)
r1_in_gga(x1, x2, x3) = r1_in_gga(x1, x2)
[] = []
r1_out_gga(x1, x2, x3) = r1_out_gga(x3)
.(x1, x2) = .(x1, x2)
U2_gga(x1, x2, x3, x4, x5) = U2_gga(x5)
rev_out_ga(x1, x2) = rev_out_ga(x2)
U2_GGA(x1, x2, x3, x4, x5) = U2_GGA(x5)
R1_IN_GGA(x1, x2, x3) = R1_IN_GGA(x1, x2)
REV_IN_GA(x1, x2) = REV_IN_GA(x1)
U1_GA(x1, x2, x3) = U1_GA(x3)
We have to consider all (P,R,Pi)-chains
The approximation of the Dependency Graph [30] contains 1 SCC with 3 less nodes.
↳ Prolog
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
↳ PiDP
↳ UsableRulesProof
Pi DP problem:
The TRS P consists of the following rules:
R1_IN_GGA(.(X, Xs), Accm, RES) → R1_IN_GGA(Xs, .(X, Accm), RES)
The TRS R consists of the following rules:
rev_in_ga(LS, RES) → U1_ga(LS, RES, r1_in_gga(LS, [], RES))
r1_in_gga([], RES, RES) → r1_out_gga([], RES, RES)
r1_in_gga(.(X, Xs), Accm, RES) → U2_gga(X, Xs, Accm, RES, r1_in_gga(Xs, .(X, Accm), RES))
U2_gga(X, Xs, Accm, RES, r1_out_gga(Xs, .(X, Accm), RES)) → r1_out_gga(.(X, Xs), Accm, RES)
U1_ga(LS, RES, r1_out_gga(LS, [], RES)) → rev_out_ga(LS, RES)
The argument filtering Pi contains the following mapping:
rev_in_ga(x1, x2) = rev_in_ga(x1)
U1_ga(x1, x2, x3) = U1_ga(x3)
r1_in_gga(x1, x2, x3) = r1_in_gga(x1, x2)
[] = []
r1_out_gga(x1, x2, x3) = r1_out_gga(x3)
.(x1, x2) = .(x1, x2)
U2_gga(x1, x2, x3, x4, x5) = U2_gga(x5)
rev_out_ga(x1, x2) = rev_out_ga(x2)
R1_IN_GGA(x1, x2, x3) = R1_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
↳ PiDP
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
Pi DP problem:
The TRS P consists of the following rules:
R1_IN_GGA(.(X, Xs), Accm, RES) → R1_IN_GGA(Xs, .(X, Accm), RES)
R is empty.
The argument filtering Pi contains the following mapping:
.(x1, x2) = .(x1, x2)
R1_IN_GGA(x1, x2, x3) = R1_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
↳ PiDP
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
↳ QDP
↳ QDPSizeChangeProof
Q DP problem:
The TRS P consists of the following rules:
R1_IN_GGA(.(X, Xs), Accm) → R1_IN_GGA(Xs, .(X, Accm))
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:
- R1_IN_GGA(.(X, Xs), Accm) → R1_IN_GGA(Xs, .(X, Accm))
The graph contains the following edges 1 > 1