Left Termination of the query pattern
p_in_1(g)
w.r.t. the given Prolog program could successfully be proven:
↳ Prolog
↳ PrologToPiTRSProof
Clauses:
p(0).
p(s(X)) :- ','(geq(X, Y), p(Y)).
geq(X, X).
geq(s(X), Y) :- geq(X, Y).
Queries:
p(g).
We use the technique of [30]. With regard to the inferred argument filtering the predicates were used in the following modes:
p_in: (b)
geq_in: (b,f)
Transforming Prolog into the following Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
p_in_g(0) → p_out_g(0)
p_in_g(s(X)) → U1_g(X, geq_in_ga(X, Y))
geq_in_ga(X, X) → geq_out_ga(X, X)
geq_in_ga(s(X), Y) → U3_ga(X, Y, geq_in_ga(X, Y))
U3_ga(X, Y, geq_out_ga(X, Y)) → geq_out_ga(s(X), Y)
U1_g(X, geq_out_ga(X, Y)) → U2_g(X, p_in_g(Y))
U2_g(X, p_out_g(Y)) → p_out_g(s(X))
The argument filtering Pi contains the following mapping:
p_in_g(x1) = p_in_g(x1)
0 = 0
p_out_g(x1) = p_out_g
s(x1) = s(x1)
U1_g(x1, x2) = U1_g(x2)
geq_in_ga(x1, x2) = geq_in_ga(x1)
geq_out_ga(x1, x2) = geq_out_ga(x2)
U3_ga(x1, x2, x3) = U3_ga(x3)
U2_g(x1, x2) = U2_g(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:
p_in_g(0) → p_out_g(0)
p_in_g(s(X)) → U1_g(X, geq_in_ga(X, Y))
geq_in_ga(X, X) → geq_out_ga(X, X)
geq_in_ga(s(X), Y) → U3_ga(X, Y, geq_in_ga(X, Y))
U3_ga(X, Y, geq_out_ga(X, Y)) → geq_out_ga(s(X), Y)
U1_g(X, geq_out_ga(X, Y)) → U2_g(X, p_in_g(Y))
U2_g(X, p_out_g(Y)) → p_out_g(s(X))
The argument filtering Pi contains the following mapping:
p_in_g(x1) = p_in_g(x1)
0 = 0
p_out_g(x1) = p_out_g
s(x1) = s(x1)
U1_g(x1, x2) = U1_g(x2)
geq_in_ga(x1, x2) = geq_in_ga(x1)
geq_out_ga(x1, x2) = geq_out_ga(x2)
U3_ga(x1, x2, x3) = U3_ga(x3)
U2_g(x1, x2) = U2_g(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:
P_IN_G(s(X)) → U1_G(X, geq_in_ga(X, Y))
P_IN_G(s(X)) → GEQ_IN_GA(X, Y)
GEQ_IN_GA(s(X), Y) → U3_GA(X, Y, geq_in_ga(X, Y))
GEQ_IN_GA(s(X), Y) → GEQ_IN_GA(X, Y)
U1_G(X, geq_out_ga(X, Y)) → U2_G(X, p_in_g(Y))
U1_G(X, geq_out_ga(X, Y)) → P_IN_G(Y)
The TRS R consists of the following rules:
p_in_g(0) → p_out_g(0)
p_in_g(s(X)) → U1_g(X, geq_in_ga(X, Y))
geq_in_ga(X, X) → geq_out_ga(X, X)
geq_in_ga(s(X), Y) → U3_ga(X, Y, geq_in_ga(X, Y))
U3_ga(X, Y, geq_out_ga(X, Y)) → geq_out_ga(s(X), Y)
U1_g(X, geq_out_ga(X, Y)) → U2_g(X, p_in_g(Y))
U2_g(X, p_out_g(Y)) → p_out_g(s(X))
The argument filtering Pi contains the following mapping:
p_in_g(x1) = p_in_g(x1)
0 = 0
p_out_g(x1) = p_out_g
s(x1) = s(x1)
U1_g(x1, x2) = U1_g(x2)
geq_in_ga(x1, x2) = geq_in_ga(x1)
geq_out_ga(x1, x2) = geq_out_ga(x2)
U3_ga(x1, x2, x3) = U3_ga(x3)
U2_g(x1, x2) = U2_g(x2)
U2_G(x1, x2) = U2_G(x2)
P_IN_G(x1) = P_IN_G(x1)
GEQ_IN_GA(x1, x2) = GEQ_IN_GA(x1)
U3_GA(x1, x2, x3) = U3_GA(x3)
U1_G(x1, x2) = U1_G(x2)
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:
P_IN_G(s(X)) → U1_G(X, geq_in_ga(X, Y))
P_IN_G(s(X)) → GEQ_IN_GA(X, Y)
GEQ_IN_GA(s(X), Y) → U3_GA(X, Y, geq_in_ga(X, Y))
GEQ_IN_GA(s(X), Y) → GEQ_IN_GA(X, Y)
U1_G(X, geq_out_ga(X, Y)) → U2_G(X, p_in_g(Y))
U1_G(X, geq_out_ga(X, Y)) → P_IN_G(Y)
The TRS R consists of the following rules:
p_in_g(0) → p_out_g(0)
p_in_g(s(X)) → U1_g(X, geq_in_ga(X, Y))
geq_in_ga(X, X) → geq_out_ga(X, X)
geq_in_ga(s(X), Y) → U3_ga(X, Y, geq_in_ga(X, Y))
U3_ga(X, Y, geq_out_ga(X, Y)) → geq_out_ga(s(X), Y)
U1_g(X, geq_out_ga(X, Y)) → U2_g(X, p_in_g(Y))
U2_g(X, p_out_g(Y)) → p_out_g(s(X))
The argument filtering Pi contains the following mapping:
p_in_g(x1) = p_in_g(x1)
0 = 0
p_out_g(x1) = p_out_g
s(x1) = s(x1)
U1_g(x1, x2) = U1_g(x2)
geq_in_ga(x1, x2) = geq_in_ga(x1)
geq_out_ga(x1, x2) = geq_out_ga(x2)
U3_ga(x1, x2, x3) = U3_ga(x3)
U2_g(x1, x2) = U2_g(x2)
U2_G(x1, x2) = U2_G(x2)
P_IN_G(x1) = P_IN_G(x1)
GEQ_IN_GA(x1, x2) = GEQ_IN_GA(x1)
U3_GA(x1, x2, x3) = U3_GA(x3)
U1_G(x1, x2) = U1_G(x2)
We have to consider all (P,R,Pi)-chains
The approximation of the Dependency Graph [30] contains 2 SCCs with 3 less nodes.
↳ Prolog
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
↳ AND
↳ PiDP
↳ UsableRulesProof
↳ PiDP
Pi DP problem:
The TRS P consists of the following rules:
GEQ_IN_GA(s(X), Y) → GEQ_IN_GA(X, Y)
The TRS R consists of the following rules:
p_in_g(0) → p_out_g(0)
p_in_g(s(X)) → U1_g(X, geq_in_ga(X, Y))
geq_in_ga(X, X) → geq_out_ga(X, X)
geq_in_ga(s(X), Y) → U3_ga(X, Y, geq_in_ga(X, Y))
U3_ga(X, Y, geq_out_ga(X, Y)) → geq_out_ga(s(X), Y)
U1_g(X, geq_out_ga(X, Y)) → U2_g(X, p_in_g(Y))
U2_g(X, p_out_g(Y)) → p_out_g(s(X))
The argument filtering Pi contains the following mapping:
p_in_g(x1) = p_in_g(x1)
0 = 0
p_out_g(x1) = p_out_g
s(x1) = s(x1)
U1_g(x1, x2) = U1_g(x2)
geq_in_ga(x1, x2) = geq_in_ga(x1)
geq_out_ga(x1, x2) = geq_out_ga(x2)
U3_ga(x1, x2, x3) = U3_ga(x3)
U2_g(x1, x2) = U2_g(x2)
GEQ_IN_GA(x1, x2) = GEQ_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
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
↳ PiDP
Pi DP problem:
The TRS P consists of the following rules:
GEQ_IN_GA(s(X), Y) → GEQ_IN_GA(X, Y)
R is empty.
The argument filtering Pi contains the following mapping:
s(x1) = s(x1)
GEQ_IN_GA(x1, x2) = GEQ_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
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
↳ QDP
↳ QDPSizeChangeProof
↳ PiDP
Q DP problem:
The TRS P consists of the following rules:
GEQ_IN_GA(s(X)) → GEQ_IN_GA(X)
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:
- GEQ_IN_GA(s(X)) → GEQ_IN_GA(X)
The graph contains the following edges 1 > 1
↳ Prolog
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
↳ AND
↳ PiDP
↳ PiDP
↳ UsableRulesProof
Pi DP problem:
The TRS P consists of the following rules:
U1_G(X, geq_out_ga(X, Y)) → P_IN_G(Y)
P_IN_G(s(X)) → U1_G(X, geq_in_ga(X, Y))
The TRS R consists of the following rules:
p_in_g(0) → p_out_g(0)
p_in_g(s(X)) → U1_g(X, geq_in_ga(X, Y))
geq_in_ga(X, X) → geq_out_ga(X, X)
geq_in_ga(s(X), Y) → U3_ga(X, Y, geq_in_ga(X, Y))
U3_ga(X, Y, geq_out_ga(X, Y)) → geq_out_ga(s(X), Y)
U1_g(X, geq_out_ga(X, Y)) → U2_g(X, p_in_g(Y))
U2_g(X, p_out_g(Y)) → p_out_g(s(X))
The argument filtering Pi contains the following mapping:
p_in_g(x1) = p_in_g(x1)
0 = 0
p_out_g(x1) = p_out_g
s(x1) = s(x1)
U1_g(x1, x2) = U1_g(x2)
geq_in_ga(x1, x2) = geq_in_ga(x1)
geq_out_ga(x1, x2) = geq_out_ga(x2)
U3_ga(x1, x2, x3) = U3_ga(x3)
U2_g(x1, x2) = U2_g(x2)
P_IN_G(x1) = P_IN_G(x1)
U1_G(x1, x2) = U1_G(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
↳ PiDP
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
Pi DP problem:
The TRS P consists of the following rules:
U1_G(X, geq_out_ga(X, Y)) → P_IN_G(Y)
P_IN_G(s(X)) → U1_G(X, geq_in_ga(X, Y))
The TRS R consists of the following rules:
geq_in_ga(X, X) → geq_out_ga(X, X)
geq_in_ga(s(X), Y) → U3_ga(X, Y, geq_in_ga(X, Y))
U3_ga(X, Y, geq_out_ga(X, Y)) → geq_out_ga(s(X), Y)
The argument filtering Pi contains the following mapping:
s(x1) = s(x1)
geq_in_ga(x1, x2) = geq_in_ga(x1)
geq_out_ga(x1, x2) = geq_out_ga(x2)
U3_ga(x1, x2, x3) = U3_ga(x3)
P_IN_G(x1) = P_IN_G(x1)
U1_G(x1, x2) = U1_G(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
↳ PiDP
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
↳ QDP
↳ UsableRulesReductionPairsProof
Q DP problem:
The TRS P consists of the following rules:
P_IN_G(s(X)) → U1_G(geq_in_ga(X))
U1_G(geq_out_ga(Y)) → P_IN_G(Y)
The TRS R consists of the following rules:
geq_in_ga(X) → geq_out_ga(X)
geq_in_ga(s(X)) → U3_ga(geq_in_ga(X))
U3_ga(geq_out_ga(Y)) → geq_out_ga(Y)
The set Q consists of the following terms:
geq_in_ga(x0)
U3_ga(x0)
We have to consider all (P,Q,R)-chains.
By using the usable rules with reduction pair processor [15] with a polynomial ordering [25], all dependency pairs and the corresponding usable rules [17] can be oriented non-strictly. All non-usable rules are removed, and those dependency pairs and usable rules that have been oriented strictly or contain non-usable symbols in their left-hand side are removed as well.
The following dependency pairs can be deleted:
P_IN_G(s(X)) → U1_G(geq_in_ga(X))
The following rules are removed from R:
geq_in_ga(s(X)) → U3_ga(geq_in_ga(X))
U3_ga(geq_out_ga(Y)) → geq_out_ga(Y)
Used ordering: POLO with Polynomial interpretation [25]:
POL(P_IN_G(x1)) = x1
POL(U1_G(x1)) = 2·x1
POL(U3_ga(x1)) = 1 + x1
POL(geq_in_ga(x1)) = x1
POL(geq_out_ga(x1)) = x1
POL(s(x1)) = 1 + 2·x1
↳ Prolog
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
↳ AND
↳ PiDP
↳ PiDP
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
↳ QDP
↳ UsableRulesReductionPairsProof
↳ QDP
↳ DependencyGraphProof
Q DP problem:
The TRS P consists of the following rules:
U1_G(geq_out_ga(Y)) → P_IN_G(Y)
The TRS R consists of the following rules:
geq_in_ga(X) → geq_out_ga(X)
The set Q consists of the following terms:
geq_in_ga(x0)
U3_ga(x0)
We have to consider all (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 0 SCCs with 1 less node.