(0) Obligation:
Clauses:
less(0, Y) :- ','(!, =(Y, s(X2))).
less(X, Y) :- ','(p(X, X1), ','(p(Y, Y1), less(X1, Y1))).
p(0, 0).
p(s(X), X).
=(X, X).
Query: less(g,a)
(1) BuiltinConflictTransformerProof (EQUIVALENT transformation)
Renamed defined predicates conflicting with built-in predicates [PROLOG].
(2) Obligation:
Clauses:
less(0, Y) :- ','(!, user_defined_=(Y, s(X2))).
less(X, Y) :- ','(p(X, X1), ','(p(Y, Y1), less(X1, Y1))).
p(0, 0).
p(s(X), X).
user_defined_=(X, X).
Query: less(g,a)
(3) PrologToPrologProblemTransformerProof (SOUND transformation)
Built Prolog problem from termination graph ICLP10.
(4) Obligation:
Clauses:
lessA(s(T25)) :- lessA(T25).
lessB(0, s(T11)).
lessB(s(T19), 0) :- lessA(T19).
lessB(s(T19), s(T29)) :- lessB(T19, T29).
Query: lessB(g,a)
(5) PrologToPiTRSProof (SOUND transformation)
We use the technique of [TOCL09]. With regard to the inferred argument filtering the predicates were used in the following modes:
lessB_in: (b,f)
lessA_in: (b)
Transforming
Prolog into the following
Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
lessB_in_ga(0, s(T11)) → lessB_out_ga(0, s(T11))
lessB_in_ga(s(T19), 0) → U2_ga(T19, lessA_in_g(T19))
lessA_in_g(s(T25)) → U1_g(T25, lessA_in_g(T25))
U1_g(T25, lessA_out_g(T25)) → lessA_out_g(s(T25))
U2_ga(T19, lessA_out_g(T19)) → lessB_out_ga(s(T19), 0)
lessB_in_ga(s(T19), s(T29)) → U3_ga(T19, T29, lessB_in_ga(T19, T29))
U3_ga(T19, T29, lessB_out_ga(T19, T29)) → lessB_out_ga(s(T19), s(T29))
The argument filtering Pi contains the following mapping:
lessB_in_ga(
x1,
x2) =
lessB_in_ga(
x1)
0 =
0
lessB_out_ga(
x1,
x2) =
lessB_out_ga
s(
x1) =
s(
x1)
U2_ga(
x1,
x2) =
U2_ga(
x2)
lessA_in_g(
x1) =
lessA_in_g(
x1)
U1_g(
x1,
x2) =
U1_g(
x2)
lessA_out_g(
x1) =
lessA_out_g
U3_ga(
x1,
x2,
x3) =
U3_ga(
x3)
Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog
(6) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
lessB_in_ga(0, s(T11)) → lessB_out_ga(0, s(T11))
lessB_in_ga(s(T19), 0) → U2_ga(T19, lessA_in_g(T19))
lessA_in_g(s(T25)) → U1_g(T25, lessA_in_g(T25))
U1_g(T25, lessA_out_g(T25)) → lessA_out_g(s(T25))
U2_ga(T19, lessA_out_g(T19)) → lessB_out_ga(s(T19), 0)
lessB_in_ga(s(T19), s(T29)) → U3_ga(T19, T29, lessB_in_ga(T19, T29))
U3_ga(T19, T29, lessB_out_ga(T19, T29)) → lessB_out_ga(s(T19), s(T29))
The argument filtering Pi contains the following mapping:
lessB_in_ga(
x1,
x2) =
lessB_in_ga(
x1)
0 =
0
lessB_out_ga(
x1,
x2) =
lessB_out_ga
s(
x1) =
s(
x1)
U2_ga(
x1,
x2) =
U2_ga(
x2)
lessA_in_g(
x1) =
lessA_in_g(
x1)
U1_g(
x1,
x2) =
U1_g(
x2)
lessA_out_g(
x1) =
lessA_out_g
U3_ga(
x1,
x2,
x3) =
U3_ga(
x3)
(7) 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:
LESSB_IN_GA(s(T19), 0) → U2_GA(T19, lessA_in_g(T19))
LESSB_IN_GA(s(T19), 0) → LESSA_IN_G(T19)
LESSA_IN_G(s(T25)) → U1_G(T25, lessA_in_g(T25))
LESSA_IN_G(s(T25)) → LESSA_IN_G(T25)
LESSB_IN_GA(s(T19), s(T29)) → U3_GA(T19, T29, lessB_in_ga(T19, T29))
LESSB_IN_GA(s(T19), s(T29)) → LESSB_IN_GA(T19, T29)
The TRS R consists of the following rules:
lessB_in_ga(0, s(T11)) → lessB_out_ga(0, s(T11))
lessB_in_ga(s(T19), 0) → U2_ga(T19, lessA_in_g(T19))
lessA_in_g(s(T25)) → U1_g(T25, lessA_in_g(T25))
U1_g(T25, lessA_out_g(T25)) → lessA_out_g(s(T25))
U2_ga(T19, lessA_out_g(T19)) → lessB_out_ga(s(T19), 0)
lessB_in_ga(s(T19), s(T29)) → U3_ga(T19, T29, lessB_in_ga(T19, T29))
U3_ga(T19, T29, lessB_out_ga(T19, T29)) → lessB_out_ga(s(T19), s(T29))
The argument filtering Pi contains the following mapping:
lessB_in_ga(
x1,
x2) =
lessB_in_ga(
x1)
0 =
0
lessB_out_ga(
x1,
x2) =
lessB_out_ga
s(
x1) =
s(
x1)
U2_ga(
x1,
x2) =
U2_ga(
x2)
lessA_in_g(
x1) =
lessA_in_g(
x1)
U1_g(
x1,
x2) =
U1_g(
x2)
lessA_out_g(
x1) =
lessA_out_g
U3_ga(
x1,
x2,
x3) =
U3_ga(
x3)
LESSB_IN_GA(
x1,
x2) =
LESSB_IN_GA(
x1)
U2_GA(
x1,
x2) =
U2_GA(
x2)
LESSA_IN_G(
x1) =
LESSA_IN_G(
x1)
U1_G(
x1,
x2) =
U1_G(
x2)
U3_GA(
x1,
x2,
x3) =
U3_GA(
x3)
We have to consider all (P,R,Pi)-chains
(8) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
LESSB_IN_GA(s(T19), 0) → U2_GA(T19, lessA_in_g(T19))
LESSB_IN_GA(s(T19), 0) → LESSA_IN_G(T19)
LESSA_IN_G(s(T25)) → U1_G(T25, lessA_in_g(T25))
LESSA_IN_G(s(T25)) → LESSA_IN_G(T25)
LESSB_IN_GA(s(T19), s(T29)) → U3_GA(T19, T29, lessB_in_ga(T19, T29))
LESSB_IN_GA(s(T19), s(T29)) → LESSB_IN_GA(T19, T29)
The TRS R consists of the following rules:
lessB_in_ga(0, s(T11)) → lessB_out_ga(0, s(T11))
lessB_in_ga(s(T19), 0) → U2_ga(T19, lessA_in_g(T19))
lessA_in_g(s(T25)) → U1_g(T25, lessA_in_g(T25))
U1_g(T25, lessA_out_g(T25)) → lessA_out_g(s(T25))
U2_ga(T19, lessA_out_g(T19)) → lessB_out_ga(s(T19), 0)
lessB_in_ga(s(T19), s(T29)) → U3_ga(T19, T29, lessB_in_ga(T19, T29))
U3_ga(T19, T29, lessB_out_ga(T19, T29)) → lessB_out_ga(s(T19), s(T29))
The argument filtering Pi contains the following mapping:
lessB_in_ga(
x1,
x2) =
lessB_in_ga(
x1)
0 =
0
lessB_out_ga(
x1,
x2) =
lessB_out_ga
s(
x1) =
s(
x1)
U2_ga(
x1,
x2) =
U2_ga(
x2)
lessA_in_g(
x1) =
lessA_in_g(
x1)
U1_g(
x1,
x2) =
U1_g(
x2)
lessA_out_g(
x1) =
lessA_out_g
U3_ga(
x1,
x2,
x3) =
U3_ga(
x3)
LESSB_IN_GA(
x1,
x2) =
LESSB_IN_GA(
x1)
U2_GA(
x1,
x2) =
U2_GA(
x2)
LESSA_IN_G(
x1) =
LESSA_IN_G(
x1)
U1_G(
x1,
x2) =
U1_G(
x2)
U3_GA(
x1,
x2,
x3) =
U3_GA(
x3)
We have to consider all (P,R,Pi)-chains
(9) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LOPSTR] contains 2 SCCs with 4 less nodes.
(10) Complex Obligation (AND)
(11) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
LESSA_IN_G(s(T25)) → LESSA_IN_G(T25)
The TRS R consists of the following rules:
lessB_in_ga(0, s(T11)) → lessB_out_ga(0, s(T11))
lessB_in_ga(s(T19), 0) → U2_ga(T19, lessA_in_g(T19))
lessA_in_g(s(T25)) → U1_g(T25, lessA_in_g(T25))
U1_g(T25, lessA_out_g(T25)) → lessA_out_g(s(T25))
U2_ga(T19, lessA_out_g(T19)) → lessB_out_ga(s(T19), 0)
lessB_in_ga(s(T19), s(T29)) → U3_ga(T19, T29, lessB_in_ga(T19, T29))
U3_ga(T19, T29, lessB_out_ga(T19, T29)) → lessB_out_ga(s(T19), s(T29))
The argument filtering Pi contains the following mapping:
lessB_in_ga(
x1,
x2) =
lessB_in_ga(
x1)
0 =
0
lessB_out_ga(
x1,
x2) =
lessB_out_ga
s(
x1) =
s(
x1)
U2_ga(
x1,
x2) =
U2_ga(
x2)
lessA_in_g(
x1) =
lessA_in_g(
x1)
U1_g(
x1,
x2) =
U1_g(
x2)
lessA_out_g(
x1) =
lessA_out_g
U3_ga(
x1,
x2,
x3) =
U3_ga(
x3)
LESSA_IN_G(
x1) =
LESSA_IN_G(
x1)
We have to consider all (P,R,Pi)-chains
(12) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(13) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
LESSA_IN_G(s(T25)) → LESSA_IN_G(T25)
R is empty.
Pi is empty.
We have to consider all (P,R,Pi)-chains
(14) PiDPToQDPProof (EQUIVALENT transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(15) Obligation:
Q DP problem:
The TRS P consists of the following rules:
LESSA_IN_G(s(T25)) → LESSA_IN_G(T25)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(16) 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:
- LESSA_IN_G(s(T25)) → LESSA_IN_G(T25)
The graph contains the following edges 1 > 1
(17) YES
(18) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
LESSB_IN_GA(s(T19), s(T29)) → LESSB_IN_GA(T19, T29)
The TRS R consists of the following rules:
lessB_in_ga(0, s(T11)) → lessB_out_ga(0, s(T11))
lessB_in_ga(s(T19), 0) → U2_ga(T19, lessA_in_g(T19))
lessA_in_g(s(T25)) → U1_g(T25, lessA_in_g(T25))
U1_g(T25, lessA_out_g(T25)) → lessA_out_g(s(T25))
U2_ga(T19, lessA_out_g(T19)) → lessB_out_ga(s(T19), 0)
lessB_in_ga(s(T19), s(T29)) → U3_ga(T19, T29, lessB_in_ga(T19, T29))
U3_ga(T19, T29, lessB_out_ga(T19, T29)) → lessB_out_ga(s(T19), s(T29))
The argument filtering Pi contains the following mapping:
lessB_in_ga(
x1,
x2) =
lessB_in_ga(
x1)
0 =
0
lessB_out_ga(
x1,
x2) =
lessB_out_ga
s(
x1) =
s(
x1)
U2_ga(
x1,
x2) =
U2_ga(
x2)
lessA_in_g(
x1) =
lessA_in_g(
x1)
U1_g(
x1,
x2) =
U1_g(
x2)
lessA_out_g(
x1) =
lessA_out_g
U3_ga(
x1,
x2,
x3) =
U3_ga(
x3)
LESSB_IN_GA(
x1,
x2) =
LESSB_IN_GA(
x1)
We have to consider all (P,R,Pi)-chains
(19) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(20) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
LESSB_IN_GA(s(T19), s(T29)) → LESSB_IN_GA(T19, T29)
R is empty.
The argument filtering Pi contains the following mapping:
s(
x1) =
s(
x1)
LESSB_IN_GA(
x1,
x2) =
LESSB_IN_GA(
x1)
We have to consider all (P,R,Pi)-chains
(21) PiDPToQDPProof (SOUND transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(22) Obligation:
Q DP problem:
The TRS P consists of the following rules:
LESSB_IN_GA(s(T19)) → LESSB_IN_GA(T19)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(23) 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:
- LESSB_IN_GA(s(T19)) → LESSB_IN_GA(T19)
The graph contains the following edges 1 > 1
(24) YES