Certification Problem

Input (TPDB TRS_Relative/Relative_05/rtL-me3)

The relative rewrite relation R/S is considered where R is the following TRS

topB(i,N1(x),y) topA(1,T1(x),y) (1)
topA(i,x,N2(y)) topB(0,x,T2(y)) (2)
topB(i,S1(x),y) topA(i,N1(x),y) (3)
topA(i,x,S2(y)) topB(i,x,N2(y)) (4)
topA(i,N1(x),T2(y)) topB(i,N1(x),S2(y)) (5)
topA(1,T1(x),T2(y)) topB(1,T1(x),S2(y)) (6)

and S is the following TRS.

topB(i,x,N2(y)) topB(i,x,N2(C(y))) (7)
topA(i,S1(x),y) topA(i,N1(x),y) (8)
topB(i,x,S2(y)) topB(i,x,N2(y)) (9)
topB(i,x,N2(y)) topB(0,x,T2(y)) (10)
topA(i,T1(x),y) topA(i,T1(x),y) (11)
topB(1,T1(x),T2(y)) topB(1,T1(x),S2(y)) (12)
topB(i,N1(x),T2(y)) topB(i,N1(x),S2(y)) (13)
topA(i,N1(x),y) topA(i,N1(C(x)),y) (14)
topB(i,x,T2(y)) topB(i,x,T2(y)) (15)
topB(i,x,S2(y)) topB(i,x,S2(D(y))) (16)
topA(i,N1(x),y) topA(1,T1(x),y) (17)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Rule Removal

Using the linear polynomial interpretation over the naturals
[topB(x1, x2, x3)] = 1 · x1 + 1 · x2 + 1 · x3
[N1(x1)] = 1 · x1
[topA(x1, x2, x3)] = 1 · x1 + 1 · x2 + 1 · x3
[1] = 0
[T1(x1)] = 1 · x1
[N2(x1)] = 1 · x1
[0] = 0
[T2(x1)] = 1 · x1
[S1(x1)] = 1 + 1 · x1
[S2(x1)] = 1 · x1
[C(x1)] = 1 · x1
[D(x1)] = 1 · x1
all of the following rules can be deleted.
topB(i,S1(x),y) topA(i,N1(x),y) (3)
topA(i,S1(x),y) topA(i,N1(x),y) (8)
topA(i,T1(x),y) topA(i,T1(x),y) (11)
topB(i,x,T2(y)) topB(i,x,T2(y)) (15)

1.1 Rule Removal

Using the linear polynomial interpretation over the naturals
[topB(x1, x2, x3)] = 1 · x1 + 1 · x2 + 1 · x3
[N1(x1)] = 1 + 1 · x1
[topA(x1, x2, x3)] = 1 + 1 · x1 + 1 · x2 + 1 · x3
[1] = 0
[T1(x1)] = 1 · x1
[N2(x1)] = 1 · x1
[0] = 0
[T2(x1)] = 1 · x1
[S2(x1)] = 1 · x1
[C(x1)] = 1 · x1
[D(x1)] = 1 · x1
all of the following rules can be deleted.
topA(i,x,N2(y)) topB(0,x,T2(y)) (2)
topA(i,x,S2(y)) topB(i,x,N2(y)) (4)
topA(i,N1(x),T2(y)) topB(i,N1(x),S2(y)) (5)
topA(1,T1(x),T2(y)) topB(1,T1(x),S2(y)) (6)
topA(i,N1(x),y) topA(1,T1(x),y) (17)

1.1.1 Rule Removal

Using the linear polynomial interpretation over the naturals
[topB(x1, x2, x3)] = 1 · x1 + 1 · x2 + 1 · x3
[N1(x1)] = 1 + 1 · x1
[topA(x1, x2, x3)] = 1 · x1 + 1 · x2 + 1 · x3
[1] = 0
[T1(x1)] = 1 · x1
[N2(x1)] = 1 + 1 · x1
[C(x1)] = 1 · x1
[S2(x1)] = 1 + 1 · x1
[0] = 0
[T2(x1)] = 1 + 1 · x1
[D(x1)] = 1 · x1
all of the following rules can be deleted.
topB(i,N1(x),y) topA(1,T1(x),y) (1)

1.1.1.1 R is empty

There are no rules in the TRS. Hence, it is terminating.