(0) Obligation:
Clauses:
prefix(Xs, Ys) :- app(Xs, X1, Ys).
app([], X, X).
app(.(X, Xs), Ys, .(X, Zs)) :- app(Xs, Ys, Zs).
Query: prefix(g,a)
(1) PrologToPrologProblemTransformerProof (SOUND transformation)
Built Prolog problem from termination graph ICLP10.
(2) Obligation:
Clauses:
appA([], T12, T12).
appA(.(T19, T20), X31, .(T19, T22)) :- appA(T20, X31, T22).
prefixB(T5, T7) :- appA(T5, X6, T7).
Query: prefixB(g,a)
(3) PrologToPiTRSProof (SOUND transformation)
We use the technique of [TOCL09]. With regard to the inferred argument filtering the predicates were used in the following modes:
prefixB_in: (b,f)
appA_in: (b,f,f)
Transforming
Prolog into the following
Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
prefixB_in_ga(T5, T7) → U2_ga(T5, T7, appA_in_gaa(T5, X6, T7))
appA_in_gaa([], T12, T12) → appA_out_gaa([], T12, T12)
appA_in_gaa(.(T19, T20), X31, .(T19, T22)) → U1_gaa(T19, T20, X31, T22, appA_in_gaa(T20, X31, T22))
U1_gaa(T19, T20, X31, T22, appA_out_gaa(T20, X31, T22)) → appA_out_gaa(.(T19, T20), X31, .(T19, T22))
U2_ga(T5, T7, appA_out_gaa(T5, X6, T7)) → prefixB_out_ga(T5, T7)
The argument filtering Pi contains the following mapping:
prefixB_in_ga(
x1,
x2) =
prefixB_in_ga(
x1)
U2_ga(
x1,
x2,
x3) =
U2_ga(
x3)
appA_in_gaa(
x1,
x2,
x3) =
appA_in_gaa(
x1)
[] =
[]
appA_out_gaa(
x1,
x2,
x3) =
appA_out_gaa
.(
x1,
x2) =
.(
x1,
x2)
U1_gaa(
x1,
x2,
x3,
x4,
x5) =
U1_gaa(
x5)
prefixB_out_ga(
x1,
x2) =
prefixB_out_ga
Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog
(4) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
prefixB_in_ga(T5, T7) → U2_ga(T5, T7, appA_in_gaa(T5, X6, T7))
appA_in_gaa([], T12, T12) → appA_out_gaa([], T12, T12)
appA_in_gaa(.(T19, T20), X31, .(T19, T22)) → U1_gaa(T19, T20, X31, T22, appA_in_gaa(T20, X31, T22))
U1_gaa(T19, T20, X31, T22, appA_out_gaa(T20, X31, T22)) → appA_out_gaa(.(T19, T20), X31, .(T19, T22))
U2_ga(T5, T7, appA_out_gaa(T5, X6, T7)) → prefixB_out_ga(T5, T7)
The argument filtering Pi contains the following mapping:
prefixB_in_ga(
x1,
x2) =
prefixB_in_ga(
x1)
U2_ga(
x1,
x2,
x3) =
U2_ga(
x3)
appA_in_gaa(
x1,
x2,
x3) =
appA_in_gaa(
x1)
[] =
[]
appA_out_gaa(
x1,
x2,
x3) =
appA_out_gaa
.(
x1,
x2) =
.(
x1,
x2)
U1_gaa(
x1,
x2,
x3,
x4,
x5) =
U1_gaa(
x5)
prefixB_out_ga(
x1,
x2) =
prefixB_out_ga
(5) DependencyPairsProof (EQUIVALENT transformation)
Using Dependency Pairs [AG00,LOPSTR] we result in the following initial DP problem:
Pi DP problem:
The TRS P consists of the following rules:
PREFIXB_IN_GA(T5, T7) → U2_GA(T5, T7, appA_in_gaa(T5, X6, T7))
PREFIXB_IN_GA(T5, T7) → APPA_IN_GAA(T5, X6, T7)
APPA_IN_GAA(.(T19, T20), X31, .(T19, T22)) → U1_GAA(T19, T20, X31, T22, appA_in_gaa(T20, X31, T22))
APPA_IN_GAA(.(T19, T20), X31, .(T19, T22)) → APPA_IN_GAA(T20, X31, T22)
The TRS R consists of the following rules:
prefixB_in_ga(T5, T7) → U2_ga(T5, T7, appA_in_gaa(T5, X6, T7))
appA_in_gaa([], T12, T12) → appA_out_gaa([], T12, T12)
appA_in_gaa(.(T19, T20), X31, .(T19, T22)) → U1_gaa(T19, T20, X31, T22, appA_in_gaa(T20, X31, T22))
U1_gaa(T19, T20, X31, T22, appA_out_gaa(T20, X31, T22)) → appA_out_gaa(.(T19, T20), X31, .(T19, T22))
U2_ga(T5, T7, appA_out_gaa(T5, X6, T7)) → prefixB_out_ga(T5, T7)
The argument filtering Pi contains the following mapping:
prefixB_in_ga(
x1,
x2) =
prefixB_in_ga(
x1)
U2_ga(
x1,
x2,
x3) =
U2_ga(
x3)
appA_in_gaa(
x1,
x2,
x3) =
appA_in_gaa(
x1)
[] =
[]
appA_out_gaa(
x1,
x2,
x3) =
appA_out_gaa
.(
x1,
x2) =
.(
x1,
x2)
U1_gaa(
x1,
x2,
x3,
x4,
x5) =
U1_gaa(
x5)
prefixB_out_ga(
x1,
x2) =
prefixB_out_ga
PREFIXB_IN_GA(
x1,
x2) =
PREFIXB_IN_GA(
x1)
U2_GA(
x1,
x2,
x3) =
U2_GA(
x3)
APPA_IN_GAA(
x1,
x2,
x3) =
APPA_IN_GAA(
x1)
U1_GAA(
x1,
x2,
x3,
x4,
x5) =
U1_GAA(
x5)
We have to consider all (P,R,Pi)-chains
(6) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
PREFIXB_IN_GA(T5, T7) → U2_GA(T5, T7, appA_in_gaa(T5, X6, T7))
PREFIXB_IN_GA(T5, T7) → APPA_IN_GAA(T5, X6, T7)
APPA_IN_GAA(.(T19, T20), X31, .(T19, T22)) → U1_GAA(T19, T20, X31, T22, appA_in_gaa(T20, X31, T22))
APPA_IN_GAA(.(T19, T20), X31, .(T19, T22)) → APPA_IN_GAA(T20, X31, T22)
The TRS R consists of the following rules:
prefixB_in_ga(T5, T7) → U2_ga(T5, T7, appA_in_gaa(T5, X6, T7))
appA_in_gaa([], T12, T12) → appA_out_gaa([], T12, T12)
appA_in_gaa(.(T19, T20), X31, .(T19, T22)) → U1_gaa(T19, T20, X31, T22, appA_in_gaa(T20, X31, T22))
U1_gaa(T19, T20, X31, T22, appA_out_gaa(T20, X31, T22)) → appA_out_gaa(.(T19, T20), X31, .(T19, T22))
U2_ga(T5, T7, appA_out_gaa(T5, X6, T7)) → prefixB_out_ga(T5, T7)
The argument filtering Pi contains the following mapping:
prefixB_in_ga(
x1,
x2) =
prefixB_in_ga(
x1)
U2_ga(
x1,
x2,
x3) =
U2_ga(
x3)
appA_in_gaa(
x1,
x2,
x3) =
appA_in_gaa(
x1)
[] =
[]
appA_out_gaa(
x1,
x2,
x3) =
appA_out_gaa
.(
x1,
x2) =
.(
x1,
x2)
U1_gaa(
x1,
x2,
x3,
x4,
x5) =
U1_gaa(
x5)
prefixB_out_ga(
x1,
x2) =
prefixB_out_ga
PREFIXB_IN_GA(
x1,
x2) =
PREFIXB_IN_GA(
x1)
U2_GA(
x1,
x2,
x3) =
U2_GA(
x3)
APPA_IN_GAA(
x1,
x2,
x3) =
APPA_IN_GAA(
x1)
U1_GAA(
x1,
x2,
x3,
x4,
x5) =
U1_GAA(
x5)
We have to consider all (P,R,Pi)-chains
(7) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LOPSTR] contains 1 SCC with 3 less nodes.
(8) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
APPA_IN_GAA(.(T19, T20), X31, .(T19, T22)) → APPA_IN_GAA(T20, X31, T22)
The TRS R consists of the following rules:
prefixB_in_ga(T5, T7) → U2_ga(T5, T7, appA_in_gaa(T5, X6, T7))
appA_in_gaa([], T12, T12) → appA_out_gaa([], T12, T12)
appA_in_gaa(.(T19, T20), X31, .(T19, T22)) → U1_gaa(T19, T20, X31, T22, appA_in_gaa(T20, X31, T22))
U1_gaa(T19, T20, X31, T22, appA_out_gaa(T20, X31, T22)) → appA_out_gaa(.(T19, T20), X31, .(T19, T22))
U2_ga(T5, T7, appA_out_gaa(T5, X6, T7)) → prefixB_out_ga(T5, T7)
The argument filtering Pi contains the following mapping:
prefixB_in_ga(
x1,
x2) =
prefixB_in_ga(
x1)
U2_ga(
x1,
x2,
x3) =
U2_ga(
x3)
appA_in_gaa(
x1,
x2,
x3) =
appA_in_gaa(
x1)
[] =
[]
appA_out_gaa(
x1,
x2,
x3) =
appA_out_gaa
.(
x1,
x2) =
.(
x1,
x2)
U1_gaa(
x1,
x2,
x3,
x4,
x5) =
U1_gaa(
x5)
prefixB_out_ga(
x1,
x2) =
prefixB_out_ga
APPA_IN_GAA(
x1,
x2,
x3) =
APPA_IN_GAA(
x1)
We have to consider all (P,R,Pi)-chains
(9) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(10) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
APPA_IN_GAA(.(T19, T20), X31, .(T19, T22)) → APPA_IN_GAA(T20, X31, T22)
R is empty.
The argument filtering Pi contains the following mapping:
.(
x1,
x2) =
.(
x1,
x2)
APPA_IN_GAA(
x1,
x2,
x3) =
APPA_IN_GAA(
x1)
We have to consider all (P,R,Pi)-chains
(11) PiDPToQDPProof (SOUND transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(12) Obligation:
Q DP problem:
The TRS P consists of the following rules:
APPA_IN_GAA(.(T19, T20)) → APPA_IN_GAA(T20)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(13) QDPSizeChangeProof (EQUIVALENT transformation)
By using the subterm criterion [SUBTERM_CRITERION] together with the size-change analysis [AAECC05] 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:
- APPA_IN_GAA(.(T19, T20)) → APPA_IN_GAA(T20)
The graph contains the following edges 1 > 1
(14) YES