(0) Obligation:
Clauses:
f(c(s(X), Y)) :- f(c(X, s(Y))).
g(c(X, s(Y))) :- g(c(s(X), Y)).
h(X) :- ','(f(X), g(X)).
Queries:
h(g).
(1) PrologToPiTRSProof (SOUND transformation)
We use the technique of [LOPSTR]. With regard to the inferred argument filtering the predicates were used in the following modes:
h_in: (b)
f_in: (b)
g_in: (b)
Transforming
Prolog into the following
Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
The argument filtering Pi contains the following mapping:
h_in_g(
x1) =
h_in_g(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
f_in_g(
x1) =
f_in_g(
x1)
c(
x1,
x2) =
c(
x1,
x2)
s(
x1) =
s(
x1)
U1_g(
x1,
x2,
x3) =
U1_g(
x3)
f_out_g(
x1) =
f_out_g
U4_g(
x1,
x2) =
U4_g(
x2)
g_in_g(
x1) =
g_in_g(
x1)
U2_g(
x1,
x2,
x3) =
U2_g(
x3)
g_out_g(
x1) =
g_out_g
h_out_g(
x1) =
h_out_g
Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog
(2) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
The argument filtering Pi contains the following mapping:
h_in_g(
x1) =
h_in_g(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
f_in_g(
x1) =
f_in_g(
x1)
c(
x1,
x2) =
c(
x1,
x2)
s(
x1) =
s(
x1)
U1_g(
x1,
x2,
x3) =
U1_g(
x3)
f_out_g(
x1) =
f_out_g
U4_g(
x1,
x2) =
U4_g(
x2)
g_in_g(
x1) =
g_in_g(
x1)
U2_g(
x1,
x2,
x3) =
U2_g(
x3)
g_out_g(
x1) =
g_out_g
h_out_g(
x1) =
h_out_g
(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:
H_IN_G(X) → U3_G(X, f_in_g(X))
H_IN_G(X) → F_IN_G(X)
F_IN_G(c(s(X), Y)) → U1_G(X, Y, f_in_g(c(X, s(Y))))
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
U3_G(X, f_out_g(X)) → U4_G(X, g_in_g(X))
U3_G(X, f_out_g(X)) → G_IN_G(X)
G_IN_G(c(X, s(Y))) → U2_G(X, Y, g_in_g(c(s(X), Y)))
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
The argument filtering Pi contains the following mapping:
h_in_g(
x1) =
h_in_g(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
f_in_g(
x1) =
f_in_g(
x1)
c(
x1,
x2) =
c(
x1,
x2)
s(
x1) =
s(
x1)
U1_g(
x1,
x2,
x3) =
U1_g(
x3)
f_out_g(
x1) =
f_out_g
U4_g(
x1,
x2) =
U4_g(
x2)
g_in_g(
x1) =
g_in_g(
x1)
U2_g(
x1,
x2,
x3) =
U2_g(
x3)
g_out_g(
x1) =
g_out_g
h_out_g(
x1) =
h_out_g
H_IN_G(
x1) =
H_IN_G(
x1)
U3_G(
x1,
x2) =
U3_G(
x1,
x2)
F_IN_G(
x1) =
F_IN_G(
x1)
U1_G(
x1,
x2,
x3) =
U1_G(
x3)
U4_G(
x1,
x2) =
U4_G(
x2)
G_IN_G(
x1) =
G_IN_G(
x1)
U2_G(
x1,
x2,
x3) =
U2_G(
x3)
We have to consider all (P,R,Pi)-chains
(4) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
H_IN_G(X) → U3_G(X, f_in_g(X))
H_IN_G(X) → F_IN_G(X)
F_IN_G(c(s(X), Y)) → U1_G(X, Y, f_in_g(c(X, s(Y))))
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
U3_G(X, f_out_g(X)) → U4_G(X, g_in_g(X))
U3_G(X, f_out_g(X)) → G_IN_G(X)
G_IN_G(c(X, s(Y))) → U2_G(X, Y, g_in_g(c(s(X), Y)))
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
The argument filtering Pi contains the following mapping:
h_in_g(
x1) =
h_in_g(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
f_in_g(
x1) =
f_in_g(
x1)
c(
x1,
x2) =
c(
x1,
x2)
s(
x1) =
s(
x1)
U1_g(
x1,
x2,
x3) =
U1_g(
x3)
f_out_g(
x1) =
f_out_g
U4_g(
x1,
x2) =
U4_g(
x2)
g_in_g(
x1) =
g_in_g(
x1)
U2_g(
x1,
x2,
x3) =
U2_g(
x3)
g_out_g(
x1) =
g_out_g
h_out_g(
x1) =
h_out_g
H_IN_G(
x1) =
H_IN_G(
x1)
U3_G(
x1,
x2) =
U3_G(
x1,
x2)
F_IN_G(
x1) =
F_IN_G(
x1)
U1_G(
x1,
x2,
x3) =
U1_G(
x3)
U4_G(
x1,
x2) =
U4_G(
x2)
G_IN_G(
x1) =
G_IN_G(
x1)
U2_G(
x1,
x2,
x3) =
U2_G(
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 6 less nodes.
(6) Complex Obligation (AND)
(7) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
The argument filtering Pi contains the following mapping:
h_in_g(
x1) =
h_in_g(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
f_in_g(
x1) =
f_in_g(
x1)
c(
x1,
x2) =
c(
x1,
x2)
s(
x1) =
s(
x1)
U1_g(
x1,
x2,
x3) =
U1_g(
x3)
f_out_g(
x1) =
f_out_g
U4_g(
x1,
x2) =
U4_g(
x2)
g_in_g(
x1) =
g_in_g(
x1)
U2_g(
x1,
x2,
x3) =
U2_g(
x3)
g_out_g(
x1) =
g_out_g
h_out_g(
x1) =
h_out_g
G_IN_G(
x1) =
G_IN_G(
x1)
We have to consider all (P,R,Pi)-chains
(8) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(9) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
R is empty.
Pi is empty.
We have to consider all (P,R,Pi)-chains
(10) PiDPToQDPProof (EQUIVALENT transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(11) Obligation:
Q DP problem:
The TRS P consists of the following rules:
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(12) MRRProof (EQUIVALENT transformation)
By using the rule removal processor [LPAR04] with the following ordering, at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented.
Strictly oriented dependency pairs:
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
Used ordering: Polynomial interpretation [POLO]:
POL(G_IN_G(x1)) = 2·x1
POL(c(x1, x2)) = x1 + 2·x2
POL(s(x1)) = 1 + x1
(13) Obligation:
Q DP problem:
P is empty.
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(14) PisEmptyProof (EQUIVALENT transformation)
The TRS P is empty. Hence, there is no (P,Q,R) chain.
(15) TRUE
(16) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
The argument filtering Pi contains the following mapping:
h_in_g(
x1) =
h_in_g(
x1)
U3_g(
x1,
x2) =
U3_g(
x1,
x2)
f_in_g(
x1) =
f_in_g(
x1)
c(
x1,
x2) =
c(
x1,
x2)
s(
x1) =
s(
x1)
U1_g(
x1,
x2,
x3) =
U1_g(
x3)
f_out_g(
x1) =
f_out_g
U4_g(
x1,
x2) =
U4_g(
x2)
g_in_g(
x1) =
g_in_g(
x1)
U2_g(
x1,
x2,
x3) =
U2_g(
x3)
g_out_g(
x1) =
g_out_g
h_out_g(
x1) =
h_out_g
F_IN_G(
x1) =
F_IN_G(
x1)
We have to consider all (P,R,Pi)-chains
(17) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(18) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
R is empty.
Pi is empty.
We have to consider all (P,R,Pi)-chains
(19) PiDPToQDPProof (EQUIVALENT transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(20) Obligation:
Q DP problem:
The TRS P consists of the following rules:
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(21) MRRProof (EQUIVALENT transformation)
By using the rule removal processor [LPAR04] with the following ordering, at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented.
Strictly oriented dependency pairs:
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
Used ordering: Polynomial interpretation [POLO]:
POL(F_IN_G(x1)) = 2·x1
POL(c(x1, x2)) = 2·x1 + x2
POL(s(x1)) = 1 + x1
(22) Obligation:
Q DP problem:
P is empty.
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(23) PisEmptyProof (EQUIVALENT transformation)
The TRS P is empty. Hence, there is no (P,Q,R) chain.
(24) TRUE
(25) PrologToPiTRSProof (SOUND transformation)
We use the technique of [LOPSTR]. With regard to the inferred argument filtering the predicates were used in the following modes:
h_in: (b)
f_in: (b)
g_in: (b)
Transforming
Prolog into the following
Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
Pi is empty.
Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog
(26) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
Pi is empty.
(27) 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:
H_IN_G(X) → U3_G(X, f_in_g(X))
H_IN_G(X) → F_IN_G(X)
F_IN_G(c(s(X), Y)) → U1_G(X, Y, f_in_g(c(X, s(Y))))
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
U3_G(X, f_out_g(X)) → U4_G(X, g_in_g(X))
U3_G(X, f_out_g(X)) → G_IN_G(X)
G_IN_G(c(X, s(Y))) → U2_G(X, Y, g_in_g(c(s(X), Y)))
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
Pi is empty.
We have to consider all (P,R,Pi)-chains
(28) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
H_IN_G(X) → U3_G(X, f_in_g(X))
H_IN_G(X) → F_IN_G(X)
F_IN_G(c(s(X), Y)) → U1_G(X, Y, f_in_g(c(X, s(Y))))
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
U3_G(X, f_out_g(X)) → U4_G(X, g_in_g(X))
U3_G(X, f_out_g(X)) → G_IN_G(X)
G_IN_G(c(X, s(Y))) → U2_G(X, Y, g_in_g(c(s(X), Y)))
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
Pi is empty.
We have to consider all (P,R,Pi)-chains
(29) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LOPSTR] contains 2 SCCs with 6 less nodes.
(30) Complex Obligation (AND)
(31) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
Pi is empty.
We have to consider all (P,R,Pi)-chains
(32) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(33) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
R is empty.
Pi is empty.
We have to consider all (P,R,Pi)-chains
(34) PiDPToQDPProof (EQUIVALENT transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(35) Obligation:
Q DP problem:
The TRS P consists of the following rules:
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(36) MRRProof (EQUIVALENT transformation)
By using the rule removal processor [LPAR04] with the following ordering, at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented.
Strictly oriented dependency pairs:
G_IN_G(c(X, s(Y))) → G_IN_G(c(s(X), Y))
Used ordering: Polynomial interpretation [POLO]:
POL(G_IN_G(x1)) = 2·x1
POL(c(x1, x2)) = x1 + 2·x2
POL(s(x1)) = 1 + x1
(37) Obligation:
Q DP problem:
P is empty.
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
(38) PisEmptyProof (EQUIVALENT transformation)
The TRS P is empty. Hence, there is no (P,Q,R) chain.
(39) TRUE
(40) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
The TRS R consists of the following rules:
h_in_g(X) → U3_g(X, f_in_g(X))
f_in_g(c(s(X), Y)) → U1_g(X, Y, f_in_g(c(X, s(Y))))
U1_g(X, Y, f_out_g(c(X, s(Y)))) → f_out_g(c(s(X), Y))
U3_g(X, f_out_g(X)) → U4_g(X, g_in_g(X))
g_in_g(c(X, s(Y))) → U2_g(X, Y, g_in_g(c(s(X), Y)))
U2_g(X, Y, g_out_g(c(s(X), Y))) → g_out_g(c(X, s(Y)))
U4_g(X, g_out_g(X)) → h_out_g(X)
Pi is empty.
We have to consider all (P,R,Pi)-chains
(41) UsableRulesProof (EQUIVALENT transformation)
For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.
(42) Obligation:
Pi DP problem:
The TRS P consists of the following rules:
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
R is empty.
Pi is empty.
We have to consider all (P,R,Pi)-chains
(43) PiDPToQDPProof (EQUIVALENT transformation)
Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.
(44) Obligation:
Q DP problem:
The TRS P consists of the following rules:
F_IN_G(c(s(X), Y)) → F_IN_G(c(X, s(Y)))
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.