(0) Obligation:
Clauses:
less(0, s(X2)).
less(X, Y) :- ','(no(zero(X)), ','(p(X, X1), ','(p(Y, Y1), less(X1, Y1)))).
p(0, 0).
p(s(X), X).
zero(0).
no(X) :- ','(X, ','(!, failure(a))).
no(X3).
failure(b).
Query: less(g,a)
(1) PrologToDTProblemTransformerProof (SOUND transformation)
Built DT problem from termination graph DT10.
(2) Obligation:
Triples:
lessA(s(X1)) :- lessA(X1).
lessB(s(X1), 0) :- lessA(X1).
lessB(s(X1), s(X2)) :- lessB(X1, X2).
Clauses:
lesscA(s(X1)) :- lesscA(X1).
lesscB(0, s(X1)).
lesscB(s(X1), 0) :- lesscA(X1).
lesscB(s(X1), s(X2)) :- lesscB(X1, X2).
Afs:
lessB(x1, x2) = lessB(x1)
(3) TriplesToPiDPProof (SOUND transformation)
We use the technique of [DT09]. With regard to the inferred argument filtering the predicates were used in the following modes:
lessB_in: (b,f)
lessA_in: (b)
Transforming
TRIPLES into the following
Term Rewriting System:
Pi DP problem:
The TRS P consists of the following rules:
LESSB_IN_GA(s(X1), 0) → U2_GA(X1, lessA_in_g(X1))
LESSB_IN_GA(s(X1), 0) → LESSA_IN_G(X1)
LESSA_IN_G(s(X1)) → U1_G(X1, lessA_in_g(X1))
LESSA_IN_G(s(X1)) → LESSA_IN_G(X1)
LESSB_IN_GA(s(X1), s(X2)) → U3_GA(X1, X2, lessB_in_ga(X1, X2))
LESSB_IN_GA(s(X1), s(X2)) → LESSB_IN_GA(X1, X2)
R is empty.
The argument filtering Pi contains the following mapping:
lessB_in_ga(
x1,
x2) =
lessB_in_ga(
x1)
s(
x1) =
s(
x1)
lessA_in_g(
x1) =
lessA_in_g(
x1)
0 =
0
LESSB_IN_GA(
x1,
x2) =
LESSB_IN_GA(
x1)
U2_GA(
x1,
x2) =
U2_GA(
x1,
x2)
LESSA_IN_G(
x1) =
LESSA_IN_G(
x1)
U1_G(
x1,
x2) =
U1_G(
x1,
x2)
U3_GA(
x1,
x2,
x3) =
U3_GA(
x1,
x3)
We have to consider all (P,R,Pi)-chains
Infinitary Constructor Rewriting Termination of PiDP implies Termination of TRIPLES
(4) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
LESSB_IN_GA(s(X1), 0) → U2_GA(X1, lessA_in_g(X1))
LESSB_IN_GA(s(X1), 0) → LESSA_IN_G(X1)
LESSA_IN_G(s(X1)) → U1_G(X1, lessA_in_g(X1))
LESSA_IN_G(s(X1)) → LESSA_IN_G(X1)
LESSB_IN_GA(s(X1), s(X2)) → U3_GA(X1, X2, lessB_in_ga(X1, X2))
LESSB_IN_GA(s(X1), s(X2)) → LESSB_IN_GA(X1, X2)
R is empty.
The argument filtering Pi contains the following mapping:
lessB_in_ga(
x1,
x2) =
lessB_in_ga(
x1)
s(
x1) =
s(
x1)
lessA_in_g(
x1) =
lessA_in_g(
x1)
0 =
0
LESSB_IN_GA(
x1,
x2) =
LESSB_IN_GA(
x1)
U2_GA(
x1,
x2) =
U2_GA(
x1,
x2)
LESSA_IN_G(
x1) =
LESSA_IN_G(
x1)
U1_G(
x1,
x2) =
U1_G(
x1,
x2)
U3_GA(
x1,
x2,
x3) =
U3_GA(
x1,
x3)
We have to consider all (P,R,Pi)-chains
(5) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LOPSTR] contains 2 SCCs with 4 less nodes.
(6) Complex Obligation (AND)
(7) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
LESSA_IN_G(s(X1)) → LESSA_IN_G(X1)
R is empty.
Pi is empty.
We have to consider all (P,R,Pi)-chains
(8) PiDPToQDPProof (EQUIVALENT transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(9) Obligation:
Q DP problem:
The TRS P consists of the following rules:
LESSA_IN_G(s(X1)) → LESSA_IN_G(X1)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(10) 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(X1)) → LESSA_IN_G(X1)
The graph contains the following edges 1 > 1
(11) YES
(12) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
LESSB_IN_GA(s(X1), s(X2)) → LESSB_IN_GA(X1, X2)
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
(13) PiDPToQDPProof (SOUND transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(14) Obligation:
Q DP problem:
The TRS P consists of the following rules:
LESSB_IN_GA(s(X1)) → LESSB_IN_GA(X1)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(15) 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(X1)) → LESSB_IN_GA(X1)
The graph contains the following edges 1 > 1
(16) YES