Left Termination of the query pattern reverse(b,b,f) w.r.t. the given Prolog program could successfully be proven:
↳ PROLOG
↳ PrologToPiTRSProof
reverse3({}0, X, X).
reverse3(.2(X, Y), Z, U) :- reverse3(Y, Z, .2(X, U)).
With regard to the inferred argument filtering the predicates were used in the following modes:
reverse3: (b,b,f)
Transforming PROLOG into the following Term Rewriting System:
Pi-finite rewrite system:
The TRS R consists of the following rules:
reverse_3_in_gga3([]_0, X, X) -> reverse_3_out_gga3([]_0, X, X)
reverse_3_in_gga3(._22(X, Y), Z, U) -> if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_in_gga3(Y, Z, ._22(X, U)))
if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_out_gga3(Y, Z, ._22(X, U))) -> reverse_3_out_gga3(._22(X, Y), Z, U)
The argument filtering Pi contains the following mapping:
reverse_3_in_gga3(x1, x2, x3) = reverse_3_in_gga2(x1, x2)
[]_0 = []_0
._22(x1, x2) = ._22(x1, x2)
reverse_3_out_gga3(x1, x2, x3) = reverse_3_out_gga1(x3)
if_reverse_3_in_1_gga5(x1, x2, x3, x4, x5) = if_reverse_3_in_1_gga1(x5)
Infinitary Constructor Rewriting Termination of PiTRS implies Termination of PROLOG
↳ PROLOG
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
Pi-finite rewrite system:
The TRS R consists of the following rules:
reverse_3_in_gga3([]_0, X, X) -> reverse_3_out_gga3([]_0, X, X)
reverse_3_in_gga3(._22(X, Y), Z, U) -> if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_in_gga3(Y, Z, ._22(X, U)))
if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_out_gga3(Y, Z, ._22(X, U))) -> reverse_3_out_gga3(._22(X, Y), Z, U)
The argument filtering Pi contains the following mapping:
reverse_3_in_gga3(x1, x2, x3) = reverse_3_in_gga2(x1, x2)
[]_0 = []_0
._22(x1, x2) = ._22(x1, x2)
reverse_3_out_gga3(x1, x2, x3) = reverse_3_out_gga1(x3)
if_reverse_3_in_1_gga5(x1, x2, x3, x4, x5) = if_reverse_3_in_1_gga1(x5)
Pi DP problem:
The TRS P consists of the following rules:
REVERSE_3_IN_GGA3(._22(X, Y), Z, U) -> IF_REVERSE_3_IN_1_GGA5(X, Y, Z, U, reverse_3_in_gga3(Y, Z, ._22(X, U)))
REVERSE_3_IN_GGA3(._22(X, Y), Z, U) -> REVERSE_3_IN_GGA3(Y, Z, ._22(X, U))
The TRS R consists of the following rules:
reverse_3_in_gga3([]_0, X, X) -> reverse_3_out_gga3([]_0, X, X)
reverse_3_in_gga3(._22(X, Y), Z, U) -> if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_in_gga3(Y, Z, ._22(X, U)))
if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_out_gga3(Y, Z, ._22(X, U))) -> reverse_3_out_gga3(._22(X, Y), Z, U)
The argument filtering Pi contains the following mapping:
reverse_3_in_gga3(x1, x2, x3) = reverse_3_in_gga2(x1, x2)
[]_0 = []_0
._22(x1, x2) = ._22(x1, x2)
reverse_3_out_gga3(x1, x2, x3) = reverse_3_out_gga1(x3)
if_reverse_3_in_1_gga5(x1, x2, x3, x4, x5) = if_reverse_3_in_1_gga1(x5)
IF_REVERSE_3_IN_1_GGA5(x1, x2, x3, x4, x5) = IF_REVERSE_3_IN_1_GGA1(x5)
REVERSE_3_IN_GGA3(x1, x2, x3) = REVERSE_3_IN_GGA2(x1, x2)
We have to consider all (P,R,Pi)-chains
↳ PROLOG
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
Pi DP problem:
The TRS P consists of the following rules:
REVERSE_3_IN_GGA3(._22(X, Y), Z, U) -> IF_REVERSE_3_IN_1_GGA5(X, Y, Z, U, reverse_3_in_gga3(Y, Z, ._22(X, U)))
REVERSE_3_IN_GGA3(._22(X, Y), Z, U) -> REVERSE_3_IN_GGA3(Y, Z, ._22(X, U))
The TRS R consists of the following rules:
reverse_3_in_gga3([]_0, X, X) -> reverse_3_out_gga3([]_0, X, X)
reverse_3_in_gga3(._22(X, Y), Z, U) -> if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_in_gga3(Y, Z, ._22(X, U)))
if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_out_gga3(Y, Z, ._22(X, U))) -> reverse_3_out_gga3(._22(X, Y), Z, U)
The argument filtering Pi contains the following mapping:
reverse_3_in_gga3(x1, x2, x3) = reverse_3_in_gga2(x1, x2)
[]_0 = []_0
._22(x1, x2) = ._22(x1, x2)
reverse_3_out_gga3(x1, x2, x3) = reverse_3_out_gga1(x3)
if_reverse_3_in_1_gga5(x1, x2, x3, x4, x5) = if_reverse_3_in_1_gga1(x5)
IF_REVERSE_3_IN_1_GGA5(x1, x2, x3, x4, x5) = IF_REVERSE_3_IN_1_GGA1(x5)
REVERSE_3_IN_GGA3(x1, x2, x3) = REVERSE_3_IN_GGA2(x1, x2)
We have to consider all (P,R,Pi)-chains
The approximation of the Dependency Graph contains 1 SCC with 1 less node.
↳ PROLOG
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
↳ PiDP
↳ UsableRulesProof
Pi DP problem:
The TRS P consists of the following rules:
REVERSE_3_IN_GGA3(._22(X, Y), Z, U) -> REVERSE_3_IN_GGA3(Y, Z, ._22(X, U))
The TRS R consists of the following rules:
reverse_3_in_gga3([]_0, X, X) -> reverse_3_out_gga3([]_0, X, X)
reverse_3_in_gga3(._22(X, Y), Z, U) -> if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_in_gga3(Y, Z, ._22(X, U)))
if_reverse_3_in_1_gga5(X, Y, Z, U, reverse_3_out_gga3(Y, Z, ._22(X, U))) -> reverse_3_out_gga3(._22(X, Y), Z, U)
The argument filtering Pi contains the following mapping:
reverse_3_in_gga3(x1, x2, x3) = reverse_3_in_gga2(x1, x2)
[]_0 = []_0
._22(x1, x2) = ._22(x1, x2)
reverse_3_out_gga3(x1, x2, x3) = reverse_3_out_gga1(x3)
if_reverse_3_in_1_gga5(x1, x2, x3, x4, x5) = if_reverse_3_in_1_gga1(x5)
REVERSE_3_IN_GGA3(x1, x2, x3) = REVERSE_3_IN_GGA2(x1, x2)
We have to consider all (P,R,Pi)-chains
For (infinitary) constructor rewriting we can delete all non-usable rules from R.
↳ PROLOG
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
↳ PiDP
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
Pi DP problem:
The TRS P consists of the following rules:
REVERSE_3_IN_GGA3(._22(X, Y), Z, U) -> REVERSE_3_IN_GGA3(Y, Z, ._22(X, U))
R is empty.
The argument filtering Pi contains the following mapping:
._22(x1, x2) = ._22(x1, x2)
REVERSE_3_IN_GGA3(x1, x2, x3) = REVERSE_3_IN_GGA2(x1, x2)
We have to consider all (P,R,Pi)-chains
Transforming (infinitary) constructor rewriting Pi-DP problem into ordinary QDP problem by application of Pi.
↳ PROLOG
↳ PrologToPiTRSProof
↳ PiTRS
↳ DependencyPairsProof
↳ PiDP
↳ DependencyGraphProof
↳ PiDP
↳ UsableRulesProof
↳ PiDP
↳ PiDPToQDPProof
↳ QDP
↳ QDPSizeChangeProof
Q DP problem:
The TRS P consists of the following rules:
REVERSE_3_IN_GGA2(._22(X, Y), Z) -> REVERSE_3_IN_GGA2(Y, Z)
R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.
The head symbols of this DP problem are {REVERSE_3_IN_GGA2}.
By using the subterm criterion together with the size-change analysis 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:
- REVERSE_3_IN_GGA2(._22(X, Y), Z) -> REVERSE_3_IN_GGA2(Y, Z)
The graph contains the following edges 1 > 1, 2 >= 2