(0) Obligation:

Clauses:

select(X, Y, Zs) :- ','(no(empty(Y)), ','(head(Y, X), tail(Y, Zs))).
select(X, Y, Z) :- ','(no(empty(Y)), ','(head(Y, H), ','(head(Z, H), ','(tail(Y, T), ','(tail(Z, Zs), select(X, T, Zs)))))).
head([], X1).
head(.(H, X2), H).
tail([], []).
tail(.(X3, T), T).
empty([]).
no(X) :- ','(X, ','(!, failure(a))).
no(X4).
failure(b).

Query: select(g,g,a)

(1) PrologToPrologProblemTransformerProof (SOUND transformation)

Built Prolog problem from termination graph ICLP10.

(2) Obligation:

Clauses:

selectA(T120, .(T120, [])).
selectA(T127, .(T160, T161)) :- selectA(T127, T161).
selectB(T41, .(T41, T42), T42).
selectB(T51, .(T83, T84), []) :- selectA(T51, T84).
selectB(T51, .(T196, T185), .(T196, T198)) :- selectB(T51, T185, T198).

Query: selectB(g,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:
selectB_in: (b,b,f)
selectA_in: (b,b)
Transforming Prolog into the following Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:

selectB_in_gga(T41, .(T41, T42), T42) → selectB_out_gga(T41, .(T41, T42), T42)
selectB_in_gga(T51, .(T83, T84), []) → U2_gga(T51, T83, T84, selectA_in_gg(T51, T84))
selectA_in_gg(T120, .(T120, [])) → selectA_out_gg(T120, .(T120, []))
selectA_in_gg(T127, .(T160, T161)) → U1_gg(T127, T160, T161, selectA_in_gg(T127, T161))
U1_gg(T127, T160, T161, selectA_out_gg(T127, T161)) → selectA_out_gg(T127, .(T160, T161))
U2_gga(T51, T83, T84, selectA_out_gg(T51, T84)) → selectB_out_gga(T51, .(T83, T84), [])
selectB_in_gga(T51, .(T196, T185), .(T196, T198)) → U3_gga(T51, T196, T185, T198, selectB_in_gga(T51, T185, T198))
U3_gga(T51, T196, T185, T198, selectB_out_gga(T51, T185, T198)) → selectB_out_gga(T51, .(T196, T185), .(T196, T198))

The argument filtering Pi contains the following mapping:
selectB_in_gga(x1, x2, x3)  =  selectB_in_gga(x1, x2)
.(x1, x2)  =  .(x1, x2)
selectB_out_gga(x1, x2, x3)  =  selectB_out_gga(x3)
U2_gga(x1, x2, x3, x4)  =  U2_gga(x4)
selectA_in_gg(x1, x2)  =  selectA_in_gg(x1, x2)
[]  =  []
selectA_out_gg(x1, x2)  =  selectA_out_gg
U1_gg(x1, x2, x3, x4)  =  U1_gg(x4)
U3_gga(x1, x2, x3, x4, x5)  =  U3_gga(x2, x5)

Infinitary Constructor Rewriting Termination of PiTRS implies Termination of Prolog

(4) Obligation:

Pi-finite rewrite system:
The TRS R consists of the following rules:

selectB_in_gga(T41, .(T41, T42), T42) → selectB_out_gga(T41, .(T41, T42), T42)
selectB_in_gga(T51, .(T83, T84), []) → U2_gga(T51, T83, T84, selectA_in_gg(T51, T84))
selectA_in_gg(T120, .(T120, [])) → selectA_out_gg(T120, .(T120, []))
selectA_in_gg(T127, .(T160, T161)) → U1_gg(T127, T160, T161, selectA_in_gg(T127, T161))
U1_gg(T127, T160, T161, selectA_out_gg(T127, T161)) → selectA_out_gg(T127, .(T160, T161))
U2_gga(T51, T83, T84, selectA_out_gg(T51, T84)) → selectB_out_gga(T51, .(T83, T84), [])
selectB_in_gga(T51, .(T196, T185), .(T196, T198)) → U3_gga(T51, T196, T185, T198, selectB_in_gga(T51, T185, T198))
U3_gga(T51, T196, T185, T198, selectB_out_gga(T51, T185, T198)) → selectB_out_gga(T51, .(T196, T185), .(T196, T198))

The argument filtering Pi contains the following mapping:
selectB_in_gga(x1, x2, x3)  =  selectB_in_gga(x1, x2)
.(x1, x2)  =  .(x1, x2)
selectB_out_gga(x1, x2, x3)  =  selectB_out_gga(x3)
U2_gga(x1, x2, x3, x4)  =  U2_gga(x4)
selectA_in_gg(x1, x2)  =  selectA_in_gg(x1, x2)
[]  =  []
selectA_out_gg(x1, x2)  =  selectA_out_gg
U1_gg(x1, x2, x3, x4)  =  U1_gg(x4)
U3_gga(x1, x2, x3, x4, x5)  =  U3_gga(x2, x5)

(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:

SELECTB_IN_GGA(T51, .(T83, T84), []) → U2_GGA(T51, T83, T84, selectA_in_gg(T51, T84))
SELECTB_IN_GGA(T51, .(T83, T84), []) → SELECTA_IN_GG(T51, T84)
SELECTA_IN_GG(T127, .(T160, T161)) → U1_GG(T127, T160, T161, selectA_in_gg(T127, T161))
SELECTA_IN_GG(T127, .(T160, T161)) → SELECTA_IN_GG(T127, T161)
SELECTB_IN_GGA(T51, .(T196, T185), .(T196, T198)) → U3_GGA(T51, T196, T185, T198, selectB_in_gga(T51, T185, T198))
SELECTB_IN_GGA(T51, .(T196, T185), .(T196, T198)) → SELECTB_IN_GGA(T51, T185, T198)

The TRS R consists of the following rules:

selectB_in_gga(T41, .(T41, T42), T42) → selectB_out_gga(T41, .(T41, T42), T42)
selectB_in_gga(T51, .(T83, T84), []) → U2_gga(T51, T83, T84, selectA_in_gg(T51, T84))
selectA_in_gg(T120, .(T120, [])) → selectA_out_gg(T120, .(T120, []))
selectA_in_gg(T127, .(T160, T161)) → U1_gg(T127, T160, T161, selectA_in_gg(T127, T161))
U1_gg(T127, T160, T161, selectA_out_gg(T127, T161)) → selectA_out_gg(T127, .(T160, T161))
U2_gga(T51, T83, T84, selectA_out_gg(T51, T84)) → selectB_out_gga(T51, .(T83, T84), [])
selectB_in_gga(T51, .(T196, T185), .(T196, T198)) → U3_gga(T51, T196, T185, T198, selectB_in_gga(T51, T185, T198))
U3_gga(T51, T196, T185, T198, selectB_out_gga(T51, T185, T198)) → selectB_out_gga(T51, .(T196, T185), .(T196, T198))

The argument filtering Pi contains the following mapping:
selectB_in_gga(x1, x2, x3)  =  selectB_in_gga(x1, x2)
.(x1, x2)  =  .(x1, x2)
selectB_out_gga(x1, x2, x3)  =  selectB_out_gga(x3)
U2_gga(x1, x2, x3, x4)  =  U2_gga(x4)
selectA_in_gg(x1, x2)  =  selectA_in_gg(x1, x2)
[]  =  []
selectA_out_gg(x1, x2)  =  selectA_out_gg
U1_gg(x1, x2, x3, x4)  =  U1_gg(x4)
U3_gga(x1, x2, x3, x4, x5)  =  U3_gga(x2, x5)
SELECTB_IN_GGA(x1, x2, x3)  =  SELECTB_IN_GGA(x1, x2)
U2_GGA(x1, x2, x3, x4)  =  U2_GGA(x4)
SELECTA_IN_GG(x1, x2)  =  SELECTA_IN_GG(x1, x2)
U1_GG(x1, x2, x3, x4)  =  U1_GG(x4)
U3_GGA(x1, x2, x3, x4, x5)  =  U3_GGA(x2, x5)

We have to consider all (P,R,Pi)-chains

(6) Obligation:

Pi DP problem:
The TRS P consists of the following rules:

SELECTB_IN_GGA(T51, .(T83, T84), []) → U2_GGA(T51, T83, T84, selectA_in_gg(T51, T84))
SELECTB_IN_GGA(T51, .(T83, T84), []) → SELECTA_IN_GG(T51, T84)
SELECTA_IN_GG(T127, .(T160, T161)) → U1_GG(T127, T160, T161, selectA_in_gg(T127, T161))
SELECTA_IN_GG(T127, .(T160, T161)) → SELECTA_IN_GG(T127, T161)
SELECTB_IN_GGA(T51, .(T196, T185), .(T196, T198)) → U3_GGA(T51, T196, T185, T198, selectB_in_gga(T51, T185, T198))
SELECTB_IN_GGA(T51, .(T196, T185), .(T196, T198)) → SELECTB_IN_GGA(T51, T185, T198)

The TRS R consists of the following rules:

selectB_in_gga(T41, .(T41, T42), T42) → selectB_out_gga(T41, .(T41, T42), T42)
selectB_in_gga(T51, .(T83, T84), []) → U2_gga(T51, T83, T84, selectA_in_gg(T51, T84))
selectA_in_gg(T120, .(T120, [])) → selectA_out_gg(T120, .(T120, []))
selectA_in_gg(T127, .(T160, T161)) → U1_gg(T127, T160, T161, selectA_in_gg(T127, T161))
U1_gg(T127, T160, T161, selectA_out_gg(T127, T161)) → selectA_out_gg(T127, .(T160, T161))
U2_gga(T51, T83, T84, selectA_out_gg(T51, T84)) → selectB_out_gga(T51, .(T83, T84), [])
selectB_in_gga(T51, .(T196, T185), .(T196, T198)) → U3_gga(T51, T196, T185, T198, selectB_in_gga(T51, T185, T198))
U3_gga(T51, T196, T185, T198, selectB_out_gga(T51, T185, T198)) → selectB_out_gga(T51, .(T196, T185), .(T196, T198))

The argument filtering Pi contains the following mapping:
selectB_in_gga(x1, x2, x3)  =  selectB_in_gga(x1, x2)
.(x1, x2)  =  .(x1, x2)
selectB_out_gga(x1, x2, x3)  =  selectB_out_gga(x3)
U2_gga(x1, x2, x3, x4)  =  U2_gga(x4)
selectA_in_gg(x1, x2)  =  selectA_in_gg(x1, x2)
[]  =  []
selectA_out_gg(x1, x2)  =  selectA_out_gg
U1_gg(x1, x2, x3, x4)  =  U1_gg(x4)
U3_gga(x1, x2, x3, x4, x5)  =  U3_gga(x2, x5)
SELECTB_IN_GGA(x1, x2, x3)  =  SELECTB_IN_GGA(x1, x2)
U2_GGA(x1, x2, x3, x4)  =  U2_GGA(x4)
SELECTA_IN_GG(x1, x2)  =  SELECTA_IN_GG(x1, x2)
U1_GG(x1, x2, x3, x4)  =  U1_GG(x4)
U3_GGA(x1, x2, x3, x4, x5)  =  U3_GGA(x2, x5)

We have to consider all (P,R,Pi)-chains

(7) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LOPSTR] contains 2 SCCs with 4 less nodes.

(8) Complex Obligation (AND)

(9) Obligation:

Pi DP problem:
The TRS P consists of the following rules:

SELECTA_IN_GG(T127, .(T160, T161)) → SELECTA_IN_GG(T127, T161)

The TRS R consists of the following rules:

selectB_in_gga(T41, .(T41, T42), T42) → selectB_out_gga(T41, .(T41, T42), T42)
selectB_in_gga(T51, .(T83, T84), []) → U2_gga(T51, T83, T84, selectA_in_gg(T51, T84))
selectA_in_gg(T120, .(T120, [])) → selectA_out_gg(T120, .(T120, []))
selectA_in_gg(T127, .(T160, T161)) → U1_gg(T127, T160, T161, selectA_in_gg(T127, T161))
U1_gg(T127, T160, T161, selectA_out_gg(T127, T161)) → selectA_out_gg(T127, .(T160, T161))
U2_gga(T51, T83, T84, selectA_out_gg(T51, T84)) → selectB_out_gga(T51, .(T83, T84), [])
selectB_in_gga(T51, .(T196, T185), .(T196, T198)) → U3_gga(T51, T196, T185, T198, selectB_in_gga(T51, T185, T198))
U3_gga(T51, T196, T185, T198, selectB_out_gga(T51, T185, T198)) → selectB_out_gga(T51, .(T196, T185), .(T196, T198))

The argument filtering Pi contains the following mapping:
selectB_in_gga(x1, x2, x3)  =  selectB_in_gga(x1, x2)
.(x1, x2)  =  .(x1, x2)
selectB_out_gga(x1, x2, x3)  =  selectB_out_gga(x3)
U2_gga(x1, x2, x3, x4)  =  U2_gga(x4)
selectA_in_gg(x1, x2)  =  selectA_in_gg(x1, x2)
[]  =  []
selectA_out_gg(x1, x2)  =  selectA_out_gg
U1_gg(x1, x2, x3, x4)  =  U1_gg(x4)
U3_gga(x1, x2, x3, x4, x5)  =  U3_gga(x2, x5)
SELECTA_IN_GG(x1, x2)  =  SELECTA_IN_GG(x1, x2)

We have to consider all (P,R,Pi)-chains

(10) UsableRulesProof (EQUIVALENT transformation)

For (infinitary) constructor rewriting [LOPSTR] we can delete all non-usable rules from R.

(11) Obligation:

Pi DP problem:
The TRS P consists of the following rules:

SELECTA_IN_GG(T127, .(T160, T161)) → SELECTA_IN_GG(T127, T161)

R is empty.
Pi is empty.
We have to consider all (P,R,Pi)-chains

(12) PiDPToQDPProof (EQUIVALENT transformation)

Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.

(13) Obligation:

Q DP problem:
The TRS P consists of the following rules:

SELECTA_IN_GG(T127, .(T160, T161)) → SELECTA_IN_GG(T127, T161)

R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.

(14) 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:

  • SELECTA_IN_GG(T127, .(T160, T161)) → SELECTA_IN_GG(T127, T161)
    The graph contains the following edges 1 >= 1, 2 > 2

(15) YES

(16) Obligation:

Pi DP problem:
The TRS P consists of the following rules:

SELECTB_IN_GGA(T51, .(T196, T185), .(T196, T198)) → SELECTB_IN_GGA(T51, T185, T198)

The TRS R consists of the following rules:

selectB_in_gga(T41, .(T41, T42), T42) → selectB_out_gga(T41, .(T41, T42), T42)
selectB_in_gga(T51, .(T83, T84), []) → U2_gga(T51, T83, T84, selectA_in_gg(T51, T84))
selectA_in_gg(T120, .(T120, [])) → selectA_out_gg(T120, .(T120, []))
selectA_in_gg(T127, .(T160, T161)) → U1_gg(T127, T160, T161, selectA_in_gg(T127, T161))
U1_gg(T127, T160, T161, selectA_out_gg(T127, T161)) → selectA_out_gg(T127, .(T160, T161))
U2_gga(T51, T83, T84, selectA_out_gg(T51, T84)) → selectB_out_gga(T51, .(T83, T84), [])
selectB_in_gga(T51, .(T196, T185), .(T196, T198)) → U3_gga(T51, T196, T185, T198, selectB_in_gga(T51, T185, T198))
U3_gga(T51, T196, T185, T198, selectB_out_gga(T51, T185, T198)) → selectB_out_gga(T51, .(T196, T185), .(T196, T198))

The argument filtering Pi contains the following mapping:
selectB_in_gga(x1, x2, x3)  =  selectB_in_gga(x1, x2)
.(x1, x2)  =  .(x1, x2)
selectB_out_gga(x1, x2, x3)  =  selectB_out_gga(x3)
U2_gga(x1, x2, x3, x4)  =  U2_gga(x4)
selectA_in_gg(x1, x2)  =  selectA_in_gg(x1, x2)
[]  =  []
selectA_out_gg(x1, x2)  =  selectA_out_gg
U1_gg(x1, x2, x3, x4)  =  U1_gg(x4)
U3_gga(x1, x2, x3, x4, x5)  =  U3_gga(x2, x5)
SELECTB_IN_GGA(x1, x2, x3)  =  SELECTB_IN_GGA(x1, x2)

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:

SELECTB_IN_GGA(T51, .(T196, T185), .(T196, T198)) → SELECTB_IN_GGA(T51, T185, T198)

R is empty.
The argument filtering Pi contains the following mapping:
.(x1, x2)  =  .(x1, x2)
SELECTB_IN_GGA(x1, x2, x3)  =  SELECTB_IN_GGA(x1, x2)

We have to consider all (P,R,Pi)-chains

(19) PiDPToQDPProof (SOUND 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:

SELECTB_IN_GGA(T51, .(T196, T185)) → SELECTB_IN_GGA(T51, T185)

R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.

(21) 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:

  • SELECTB_IN_GGA(T51, .(T196, T185)) → SELECTB_IN_GGA(T51, T185)
    The graph contains the following edges 1 >= 1, 2 > 2

(22) YES