(0) Obligation:
Clauses:
even(s(s(X))) :- even(X).
even(0).
lte(s(X), s(Y)) :- lte(X, Y).
lte(0, Y).
goal :- ','(lte(X, s(s(s(s(0))))), even(X)).
Query: goal()
(1) PrologToPiTRSViaGraphTransformerProof (SOUND transformation)
Transformed Prolog program to (Pi-)TRS.
(2) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
goalA_in_ → U1_(pB_in_a(X22))
pB_in_a(T1) → U4_a(T1, lteD_in_a(T1))
lteD_in_a(s(s(s(0)))) → lteD_out_a(s(s(s(0))))
lteD_in_a(s(s(0))) → lteD_out_a(s(s(0)))
lteD_in_a(s(0)) → lteD_out_a(s(0))
lteD_in_a(0) → lteD_out_a(0)
U4_a(T1, lteD_out_a(T1)) → U5_a(T1, evenE_in_g(T1))
evenE_in_g(s(T7)) → U3_g(T7, evenC_in_g(T7))
evenC_in_g(s(s(T13))) → U2_g(T13, evenC_in_g(T13))
evenC_in_g(0) → evenC_out_g(0)
U2_g(T13, evenC_out_g(T13)) → evenC_out_g(s(s(T13)))
U3_g(T7, evenC_out_g(T7)) → evenE_out_g(s(T7))
U5_a(T1, evenE_out_g(T1)) → pB_out_a(T1)
U1_(pB_out_a(X22)) → goalA_out_
goalA_in_ → goalA_out_
The argument filtering Pi contains the following mapping:
goalA_in_ =
goalA_in_
U1_(
x1) =
U1_(
x1)
pB_in_a(
x1) =
pB_in_a
U4_a(
x1,
x2) =
U4_a(
x2)
lteD_in_a(
x1) =
lteD_in_a
lteD_out_a(
x1) =
lteD_out_a(
x1)
U5_a(
x1,
x2) =
U5_a(
x1,
x2)
evenE_in_g(
x1) =
evenE_in_g(
x1)
s(
x1) =
s(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
evenC_in_g(
x1) =
evenC_in_g(
x1)
U2_g(
x1,
x2) =
U2_g(
x1,
x2)
0 =
0
evenC_out_g(
x1) =
evenC_out_g(
x1)
evenE_out_g(
x1) =
evenE_out_g(
x1)
pB_out_a(
x1) =
pB_out_a(
x1)
goalA_out_ =
goalA_out_
(3) 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:
GOALA_IN_ → U1_1(pB_in_a(X22))
GOALA_IN_ → PB_IN_A(X22)
PB_IN_A(T1) → U4_A(T1, lteD_in_a(T1))
PB_IN_A(T1) → LTED_IN_A(T1)
U4_A(T1, lteD_out_a(T1)) → U5_A(T1, evenE_in_g(T1))
U4_A(T1, lteD_out_a(T1)) → EVENE_IN_G(T1)
EVENE_IN_G(s(T7)) → U3_G(T7, evenC_in_g(T7))
EVENE_IN_G(s(T7)) → EVENC_IN_G(T7)
EVENC_IN_G(s(s(T13))) → U2_G(T13, evenC_in_g(T13))
EVENC_IN_G(s(s(T13))) → EVENC_IN_G(T13)
The TRS R consists of the following rules:
goalA_in_ → U1_(pB_in_a(X22))
pB_in_a(T1) → U4_a(T1, lteD_in_a(T1))
lteD_in_a(s(s(s(0)))) → lteD_out_a(s(s(s(0))))
lteD_in_a(s(s(0))) → lteD_out_a(s(s(0)))
lteD_in_a(s(0)) → lteD_out_a(s(0))
lteD_in_a(0) → lteD_out_a(0)
U4_a(T1, lteD_out_a(T1)) → U5_a(T1, evenE_in_g(T1))
evenE_in_g(s(T7)) → U3_g(T7, evenC_in_g(T7))
evenC_in_g(s(s(T13))) → U2_g(T13, evenC_in_g(T13))
evenC_in_g(0) → evenC_out_g(0)
U2_g(T13, evenC_out_g(T13)) → evenC_out_g(s(s(T13)))
U3_g(T7, evenC_out_g(T7)) → evenE_out_g(s(T7))
U5_a(T1, evenE_out_g(T1)) → pB_out_a(T1)
U1_(pB_out_a(X22)) → goalA_out_
goalA_in_ → goalA_out_
The argument filtering Pi contains the following mapping:
goalA_in_ =
goalA_in_
U1_(
x1) =
U1_(
x1)
pB_in_a(
x1) =
pB_in_a
U4_a(
x1,
x2) =
U4_a(
x2)
lteD_in_a(
x1) =
lteD_in_a
lteD_out_a(
x1) =
lteD_out_a(
x1)
U5_a(
x1,
x2) =
U5_a(
x1,
x2)
evenE_in_g(
x1) =
evenE_in_g(
x1)
s(
x1) =
s(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
evenC_in_g(
x1) =
evenC_in_g(
x1)
U2_g(
x1,
x2) =
U2_g(
x1,
x2)
0 =
0
evenC_out_g(
x1) =
evenC_out_g(
x1)
evenE_out_g(
x1) =
evenE_out_g(
x1)
pB_out_a(
x1) =
pB_out_a(
x1)
goalA_out_ =
goalA_out_
GOALA_IN_ =
GOALA_IN_
U1_1(
x1) =
U1_1(
x1)
PB_IN_A(
x1) =
PB_IN_A
U4_A(
x1,
x2) =
U4_A(
x2)
LTED_IN_A(
x1) =
LTED_IN_A
U5_A(
x1,
x2) =
U5_A(
x1,
x2)
EVENE_IN_G(
x1) =
EVENE_IN_G(
x1)
U3_G(
x1,
x2) =
U3_G(
x1,
x2)
EVENC_IN_G(
x1) =
EVENC_IN_G(
x1)
U2_G(
x1,
x2) =
U2_G(
x1,
x2)
We have to consider all (P,R,Pi)-chains
(4) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
GOALA_IN_ → U1_1(pB_in_a(X22))
GOALA_IN_ → PB_IN_A(X22)
PB_IN_A(T1) → U4_A(T1, lteD_in_a(T1))
PB_IN_A(T1) → LTED_IN_A(T1)
U4_A(T1, lteD_out_a(T1)) → U5_A(T1, evenE_in_g(T1))
U4_A(T1, lteD_out_a(T1)) → EVENE_IN_G(T1)
EVENE_IN_G(s(T7)) → U3_G(T7, evenC_in_g(T7))
EVENE_IN_G(s(T7)) → EVENC_IN_G(T7)
EVENC_IN_G(s(s(T13))) → U2_G(T13, evenC_in_g(T13))
EVENC_IN_G(s(s(T13))) → EVENC_IN_G(T13)
The TRS R consists of the following rules:
goalA_in_ → U1_(pB_in_a(X22))
pB_in_a(T1) → U4_a(T1, lteD_in_a(T1))
lteD_in_a(s(s(s(0)))) → lteD_out_a(s(s(s(0))))
lteD_in_a(s(s(0))) → lteD_out_a(s(s(0)))
lteD_in_a(s(0)) → lteD_out_a(s(0))
lteD_in_a(0) → lteD_out_a(0)
U4_a(T1, lteD_out_a(T1)) → U5_a(T1, evenE_in_g(T1))
evenE_in_g(s(T7)) → U3_g(T7, evenC_in_g(T7))
evenC_in_g(s(s(T13))) → U2_g(T13, evenC_in_g(T13))
evenC_in_g(0) → evenC_out_g(0)
U2_g(T13, evenC_out_g(T13)) → evenC_out_g(s(s(T13)))
U3_g(T7, evenC_out_g(T7)) → evenE_out_g(s(T7))
U5_a(T1, evenE_out_g(T1)) → pB_out_a(T1)
U1_(pB_out_a(X22)) → goalA_out_
goalA_in_ → goalA_out_
The argument filtering Pi contains the following mapping:
goalA_in_ =
goalA_in_
U1_(
x1) =
U1_(
x1)
pB_in_a(
x1) =
pB_in_a
U4_a(
x1,
x2) =
U4_a(
x2)
lteD_in_a(
x1) =
lteD_in_a
lteD_out_a(
x1) =
lteD_out_a(
x1)
U5_a(
x1,
x2) =
U5_a(
x1,
x2)
evenE_in_g(
x1) =
evenE_in_g(
x1)
s(
x1) =
s(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
evenC_in_g(
x1) =
evenC_in_g(
x1)
U2_g(
x1,
x2) =
U2_g(
x1,
x2)
0 =
0
evenC_out_g(
x1) =
evenC_out_g(
x1)
evenE_out_g(
x1) =
evenE_out_g(
x1)
pB_out_a(
x1) =
pB_out_a(
x1)
goalA_out_ =
goalA_out_
GOALA_IN_ =
GOALA_IN_
U1_1(
x1) =
U1_1(
x1)
PB_IN_A(
x1) =
PB_IN_A
U4_A(
x1,
x2) =
U4_A(
x2)
LTED_IN_A(
x1) =
LTED_IN_A
U5_A(
x1,
x2) =
U5_A(
x1,
x2)
EVENE_IN_G(
x1) =
EVENE_IN_G(
x1)
U3_G(
x1,
x2) =
U3_G(
x1,
x2)
EVENC_IN_G(
x1) =
EVENC_IN_G(
x1)
U2_G(
x1,
x2) =
U2_G(
x1,
x2)
We have to consider all (P,R,Pi)-chains
(5) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LOPSTR] contains 1 SCC with 9 less nodes.
(6) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
EVENC_IN_G(s(s(T13))) → EVENC_IN_G(T13)
The TRS R consists of the following rules:
goalA_in_ → U1_(pB_in_a(X22))
pB_in_a(T1) → U4_a(T1, lteD_in_a(T1))
lteD_in_a(s(s(s(0)))) → lteD_out_a(s(s(s(0))))
lteD_in_a(s(s(0))) → lteD_out_a(s(s(0)))
lteD_in_a(s(0)) → lteD_out_a(s(0))
lteD_in_a(0) → lteD_out_a(0)
U4_a(T1, lteD_out_a(T1)) → U5_a(T1, evenE_in_g(T1))
evenE_in_g(s(T7)) → U3_g(T7, evenC_in_g(T7))
evenC_in_g(s(s(T13))) → U2_g(T13, evenC_in_g(T13))
evenC_in_g(0) → evenC_out_g(0)
U2_g(T13, evenC_out_g(T13)) → evenC_out_g(s(s(T13)))
U3_g(T7, evenC_out_g(T7)) → evenE_out_g(s(T7))
U5_a(T1, evenE_out_g(T1)) → pB_out_a(T1)
U1_(pB_out_a(X22)) → goalA_out_
goalA_in_ → goalA_out_
The argument filtering Pi contains the following mapping:
goalA_in_ =
goalA_in_
U1_(
x1) =
U1_(
x1)
pB_in_a(
x1) =
pB_in_a
U4_a(
x1,
x2) =
U4_a(
x2)
lteD_in_a(
x1) =
lteD_in_a
lteD_out_a(
x1) =
lteD_out_a(
x1)
U5_a(
x1,
x2) =
U5_a(
x1,
x2)
evenE_in_g(
x1) =
evenE_in_g(
x1)
s(
x1) =
s(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
evenC_in_g(
x1) =
evenC_in_g(
x1)
U2_g(
x1,
x2) =
U2_g(
x1,
x2)
0 =
0
evenC_out_g(
x1) =
evenC_out_g(
x1)
evenE_out_g(
x1) =
evenE_out_g(
x1)
pB_out_a(
x1) =
pB_out_a(
x1)
goalA_out_ =
goalA_out_
EVENC_IN_G(
x1) =
EVENC_IN_G(
x1)
We have to consider all (P,R,Pi)-chains
(7) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(8) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
EVENC_IN_G(s(s(T13))) → EVENC_IN_G(T13)
R is empty.
Pi is empty.
We have to consider all (P,R,Pi)-chains
(9) PiDPToQDPProof (EQUIVALENT transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(10) Obligation:
Q DP problem:
The TRS P consists of the following rules:
EVENC_IN_G(s(s(T13))) → EVENC_IN_G(T13)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(11) 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:
- EVENC_IN_G(s(s(T13))) → EVENC_IN_G(T13)
The graph contains the following edges 1 > 1
(12) YES