(0) Obligation:

Clauses:

overlap(Xs, Ys) :- ','(member2(X, Xs), member1(X, Ys)).
has_a_or_b(Xs) :- overlap(Xs, .(a, .(b, []))).
member1(X, .(Y, Xs)) :- member1(X, Xs).
member1(X, .(X, Xs)).
member2(X, .(Y, Xs)) :- member2(X, Xs).
member2(X, .(X, Xs)).

Query: overlap(g,g)

(1) PrologToPiTRSViaGraphTransformerProof (SOUND transformation)

Transformed Prolog program to (Pi-)TRS.

(2) Obligation:

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

overlapA_in_gg(T5, T6) → U1_gg(T5, T6, pB_in_agg(X5, T5, T6))
pB_in_agg(X25, .(T15, T16), T6) → U2_agg(X25, T15, T16, T6, pB_in_agg(X25, T16, T6))
pB_in_agg(T23, .(T23, T24), T6) → U3_agg(T23, T24, T6, member1C_in_gg(T23, T6))
member1C_in_gg(T40, .(T41, T42)) → U4_gg(T40, T41, T42, member1C_in_gg(T40, T42))
member1C_in_gg(T50, .(T50, T51)) → member1C_out_gg(T50, .(T50, T51))
U4_gg(T40, T41, T42, member1C_out_gg(T40, T42)) → member1C_out_gg(T40, .(T41, T42))
U3_agg(T23, T24, T6, member1C_out_gg(T23, T6)) → pB_out_agg(T23, .(T23, T24), T6)
U2_agg(X25, T15, T16, T6, pB_out_agg(X25, T16, T6)) → pB_out_agg(X25, .(T15, T16), T6)
U1_gg(T5, T6, pB_out_agg(X5, T5, T6)) → overlapA_out_gg(T5, T6)

The argument filtering Pi contains the following mapping:
overlapA_in_gg(x1, x2)  =  overlapA_in_gg(x1, x2)
U1_gg(x1, x2, x3)  =  U1_gg(x1, x2, x3)
pB_in_agg(x1, x2, x3)  =  pB_in_agg(x2, x3)
.(x1, x2)  =  .(x1, x2)
U2_agg(x1, x2, x3, x4, x5)  =  U2_agg(x2, x3, x4, x5)
U3_agg(x1, x2, x3, x4)  =  U3_agg(x1, x2, x3, x4)
member1C_in_gg(x1, x2)  =  member1C_in_gg(x1, x2)
U4_gg(x1, x2, x3, x4)  =  U4_gg(x1, x2, x3, x4)
member1C_out_gg(x1, x2)  =  member1C_out_gg(x1, x2)
pB_out_agg(x1, x2, x3)  =  pB_out_agg(x1, x2, x3)
overlapA_out_gg(x1, x2)  =  overlapA_out_gg(x1, x2)

(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:

OVERLAPA_IN_GG(T5, T6) → U1_GG(T5, T6, pB_in_agg(X5, T5, T6))
OVERLAPA_IN_GG(T5, T6) → PB_IN_AGG(X5, T5, T6)
PB_IN_AGG(X25, .(T15, T16), T6) → U2_AGG(X25, T15, T16, T6, pB_in_agg(X25, T16, T6))
PB_IN_AGG(X25, .(T15, T16), T6) → PB_IN_AGG(X25, T16, T6)
PB_IN_AGG(T23, .(T23, T24), T6) → U3_AGG(T23, T24, T6, member1C_in_gg(T23, T6))
PB_IN_AGG(T23, .(T23, T24), T6) → MEMBER1C_IN_GG(T23, T6)
MEMBER1C_IN_GG(T40, .(T41, T42)) → U4_GG(T40, T41, T42, member1C_in_gg(T40, T42))
MEMBER1C_IN_GG(T40, .(T41, T42)) → MEMBER1C_IN_GG(T40, T42)

The TRS R consists of the following rules:

overlapA_in_gg(T5, T6) → U1_gg(T5, T6, pB_in_agg(X5, T5, T6))
pB_in_agg(X25, .(T15, T16), T6) → U2_agg(X25, T15, T16, T6, pB_in_agg(X25, T16, T6))
pB_in_agg(T23, .(T23, T24), T6) → U3_agg(T23, T24, T6, member1C_in_gg(T23, T6))
member1C_in_gg(T40, .(T41, T42)) → U4_gg(T40, T41, T42, member1C_in_gg(T40, T42))
member1C_in_gg(T50, .(T50, T51)) → member1C_out_gg(T50, .(T50, T51))
U4_gg(T40, T41, T42, member1C_out_gg(T40, T42)) → member1C_out_gg(T40, .(T41, T42))
U3_agg(T23, T24, T6, member1C_out_gg(T23, T6)) → pB_out_agg(T23, .(T23, T24), T6)
U2_agg(X25, T15, T16, T6, pB_out_agg(X25, T16, T6)) → pB_out_agg(X25, .(T15, T16), T6)
U1_gg(T5, T6, pB_out_agg(X5, T5, T6)) → overlapA_out_gg(T5, T6)

The argument filtering Pi contains the following mapping:
overlapA_in_gg(x1, x2)  =  overlapA_in_gg(x1, x2)
U1_gg(x1, x2, x3)  =  U1_gg(x1, x2, x3)
pB_in_agg(x1, x2, x3)  =  pB_in_agg(x2, x3)
.(x1, x2)  =  .(x1, x2)
U2_agg(x1, x2, x3, x4, x5)  =  U2_agg(x2, x3, x4, x5)
U3_agg(x1, x2, x3, x4)  =  U3_agg(x1, x2, x3, x4)
member1C_in_gg(x1, x2)  =  member1C_in_gg(x1, x2)
U4_gg(x1, x2, x3, x4)  =  U4_gg(x1, x2, x3, x4)
member1C_out_gg(x1, x2)  =  member1C_out_gg(x1, x2)
pB_out_agg(x1, x2, x3)  =  pB_out_agg(x1, x2, x3)
overlapA_out_gg(x1, x2)  =  overlapA_out_gg(x1, x2)
OVERLAPA_IN_GG(x1, x2)  =  OVERLAPA_IN_GG(x1, x2)
U1_GG(x1, x2, x3)  =  U1_GG(x1, x2, x3)
PB_IN_AGG(x1, x2, x3)  =  PB_IN_AGG(x2, x3)
U2_AGG(x1, x2, x3, x4, x5)  =  U2_AGG(x2, x3, x4, x5)
U3_AGG(x1, x2, x3, x4)  =  U3_AGG(x1, x2, x3, x4)
MEMBER1C_IN_GG(x1, x2)  =  MEMBER1C_IN_GG(x1, x2)
U4_GG(x1, x2, x3, x4)  =  U4_GG(x1, x2, x3, x4)

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

(4) Obligation:

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

OVERLAPA_IN_GG(T5, T6) → U1_GG(T5, T6, pB_in_agg(X5, T5, T6))
OVERLAPA_IN_GG(T5, T6) → PB_IN_AGG(X5, T5, T6)
PB_IN_AGG(X25, .(T15, T16), T6) → U2_AGG(X25, T15, T16, T6, pB_in_agg(X25, T16, T6))
PB_IN_AGG(X25, .(T15, T16), T6) → PB_IN_AGG(X25, T16, T6)
PB_IN_AGG(T23, .(T23, T24), T6) → U3_AGG(T23, T24, T6, member1C_in_gg(T23, T6))
PB_IN_AGG(T23, .(T23, T24), T6) → MEMBER1C_IN_GG(T23, T6)
MEMBER1C_IN_GG(T40, .(T41, T42)) → U4_GG(T40, T41, T42, member1C_in_gg(T40, T42))
MEMBER1C_IN_GG(T40, .(T41, T42)) → MEMBER1C_IN_GG(T40, T42)

The TRS R consists of the following rules:

overlapA_in_gg(T5, T6) → U1_gg(T5, T6, pB_in_agg(X5, T5, T6))
pB_in_agg(X25, .(T15, T16), T6) → U2_agg(X25, T15, T16, T6, pB_in_agg(X25, T16, T6))
pB_in_agg(T23, .(T23, T24), T6) → U3_agg(T23, T24, T6, member1C_in_gg(T23, T6))
member1C_in_gg(T40, .(T41, T42)) → U4_gg(T40, T41, T42, member1C_in_gg(T40, T42))
member1C_in_gg(T50, .(T50, T51)) → member1C_out_gg(T50, .(T50, T51))
U4_gg(T40, T41, T42, member1C_out_gg(T40, T42)) → member1C_out_gg(T40, .(T41, T42))
U3_agg(T23, T24, T6, member1C_out_gg(T23, T6)) → pB_out_agg(T23, .(T23, T24), T6)
U2_agg(X25, T15, T16, T6, pB_out_agg(X25, T16, T6)) → pB_out_agg(X25, .(T15, T16), T6)
U1_gg(T5, T6, pB_out_agg(X5, T5, T6)) → overlapA_out_gg(T5, T6)

The argument filtering Pi contains the following mapping:
overlapA_in_gg(x1, x2)  =  overlapA_in_gg(x1, x2)
U1_gg(x1, x2, x3)  =  U1_gg(x1, x2, x3)
pB_in_agg(x1, x2, x3)  =  pB_in_agg(x2, x3)
.(x1, x2)  =  .(x1, x2)
U2_agg(x1, x2, x3, x4, x5)  =  U2_agg(x2, x3, x4, x5)
U3_agg(x1, x2, x3, x4)  =  U3_agg(x1, x2, x3, x4)
member1C_in_gg(x1, x2)  =  member1C_in_gg(x1, x2)
U4_gg(x1, x2, x3, x4)  =  U4_gg(x1, x2, x3, x4)
member1C_out_gg(x1, x2)  =  member1C_out_gg(x1, x2)
pB_out_agg(x1, x2, x3)  =  pB_out_agg(x1, x2, x3)
overlapA_out_gg(x1, x2)  =  overlapA_out_gg(x1, x2)
OVERLAPA_IN_GG(x1, x2)  =  OVERLAPA_IN_GG(x1, x2)
U1_GG(x1, x2, x3)  =  U1_GG(x1, x2, x3)
PB_IN_AGG(x1, x2, x3)  =  PB_IN_AGG(x2, x3)
U2_AGG(x1, x2, x3, x4, x5)  =  U2_AGG(x2, x3, x4, x5)
U3_AGG(x1, x2, x3, x4)  =  U3_AGG(x1, x2, x3, x4)
MEMBER1C_IN_GG(x1, x2)  =  MEMBER1C_IN_GG(x1, x2)
U4_GG(x1, x2, x3, x4)  =  U4_GG(x1, x2, x3, x4)

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:

MEMBER1C_IN_GG(T40, .(T41, T42)) → MEMBER1C_IN_GG(T40, T42)

The TRS R consists of the following rules:

overlapA_in_gg(T5, T6) → U1_gg(T5, T6, pB_in_agg(X5, T5, T6))
pB_in_agg(X25, .(T15, T16), T6) → U2_agg(X25, T15, T16, T6, pB_in_agg(X25, T16, T6))
pB_in_agg(T23, .(T23, T24), T6) → U3_agg(T23, T24, T6, member1C_in_gg(T23, T6))
member1C_in_gg(T40, .(T41, T42)) → U4_gg(T40, T41, T42, member1C_in_gg(T40, T42))
member1C_in_gg(T50, .(T50, T51)) → member1C_out_gg(T50, .(T50, T51))
U4_gg(T40, T41, T42, member1C_out_gg(T40, T42)) → member1C_out_gg(T40, .(T41, T42))
U3_agg(T23, T24, T6, member1C_out_gg(T23, T6)) → pB_out_agg(T23, .(T23, T24), T6)
U2_agg(X25, T15, T16, T6, pB_out_agg(X25, T16, T6)) → pB_out_agg(X25, .(T15, T16), T6)
U1_gg(T5, T6, pB_out_agg(X5, T5, T6)) → overlapA_out_gg(T5, T6)

The argument filtering Pi contains the following mapping:
overlapA_in_gg(x1, x2)  =  overlapA_in_gg(x1, x2)
U1_gg(x1, x2, x3)  =  U1_gg(x1, x2, x3)
pB_in_agg(x1, x2, x3)  =  pB_in_agg(x2, x3)
.(x1, x2)  =  .(x1, x2)
U2_agg(x1, x2, x3, x4, x5)  =  U2_agg(x2, x3, x4, x5)
U3_agg(x1, x2, x3, x4)  =  U3_agg(x1, x2, x3, x4)
member1C_in_gg(x1, x2)  =  member1C_in_gg(x1, x2)
U4_gg(x1, x2, x3, x4)  =  U4_gg(x1, x2, x3, x4)
member1C_out_gg(x1, x2)  =  member1C_out_gg(x1, x2)
pB_out_agg(x1, x2, x3)  =  pB_out_agg(x1, x2, x3)
overlapA_out_gg(x1, x2)  =  overlapA_out_gg(x1, x2)
MEMBER1C_IN_GG(x1, x2)  =  MEMBER1C_IN_GG(x1, x2)

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:

MEMBER1C_IN_GG(T40, .(T41, T42)) → MEMBER1C_IN_GG(T40, T42)

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:

MEMBER1C_IN_GG(T40, .(T41, T42)) → MEMBER1C_IN_GG(T40, T42)

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

(12) 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:

  • MEMBER1C_IN_GG(T40, .(T41, T42)) → MEMBER1C_IN_GG(T40, T42)
    The graph contains the following edges 1 >= 1, 2 > 2

(13) YES

(14) Obligation:

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

PB_IN_AGG(X25, .(T15, T16), T6) → PB_IN_AGG(X25, T16, T6)

The TRS R consists of the following rules:

overlapA_in_gg(T5, T6) → U1_gg(T5, T6, pB_in_agg(X5, T5, T6))
pB_in_agg(X25, .(T15, T16), T6) → U2_agg(X25, T15, T16, T6, pB_in_agg(X25, T16, T6))
pB_in_agg(T23, .(T23, T24), T6) → U3_agg(T23, T24, T6, member1C_in_gg(T23, T6))
member1C_in_gg(T40, .(T41, T42)) → U4_gg(T40, T41, T42, member1C_in_gg(T40, T42))
member1C_in_gg(T50, .(T50, T51)) → member1C_out_gg(T50, .(T50, T51))
U4_gg(T40, T41, T42, member1C_out_gg(T40, T42)) → member1C_out_gg(T40, .(T41, T42))
U3_agg(T23, T24, T6, member1C_out_gg(T23, T6)) → pB_out_agg(T23, .(T23, T24), T6)
U2_agg(X25, T15, T16, T6, pB_out_agg(X25, T16, T6)) → pB_out_agg(X25, .(T15, T16), T6)
U1_gg(T5, T6, pB_out_agg(X5, T5, T6)) → overlapA_out_gg(T5, T6)

The argument filtering Pi contains the following mapping:
overlapA_in_gg(x1, x2)  =  overlapA_in_gg(x1, x2)
U1_gg(x1, x2, x3)  =  U1_gg(x1, x2, x3)
pB_in_agg(x1, x2, x3)  =  pB_in_agg(x2, x3)
.(x1, x2)  =  .(x1, x2)
U2_agg(x1, x2, x3, x4, x5)  =  U2_agg(x2, x3, x4, x5)
U3_agg(x1, x2, x3, x4)  =  U3_agg(x1, x2, x3, x4)
member1C_in_gg(x1, x2)  =  member1C_in_gg(x1, x2)
U4_gg(x1, x2, x3, x4)  =  U4_gg(x1, x2, x3, x4)
member1C_out_gg(x1, x2)  =  member1C_out_gg(x1, x2)
pB_out_agg(x1, x2, x3)  =  pB_out_agg(x1, x2, x3)
overlapA_out_gg(x1, x2)  =  overlapA_out_gg(x1, x2)
PB_IN_AGG(x1, x2, x3)  =  PB_IN_AGG(x2, x3)

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

(15) UsableRulesProof (EQUIVALENT transformation)

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

(16) Obligation:

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

PB_IN_AGG(X25, .(T15, T16), T6) → PB_IN_AGG(X25, T16, T6)

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

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

(17) PiDPToQDPProof (SOUND transformation)

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

(18) Obligation:

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

PB_IN_AGG(.(T15, T16), T6) → PB_IN_AGG(T16, T6)

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

(19) 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:

  • PB_IN_AGG(.(T15, T16), T6) → PB_IN_AGG(T16, T6)
    The graph contains the following edges 1 > 1, 2 >= 2

(20) YES