Certification Problem
Input (TPDB TRS_Standard/CiME_04/boolean_rings)
The rewrite relation of the following TRS is considered.
xor(x,F) |
→ |
x |
(1) |
xor(x,neg(x)) |
→ |
F |
(2) |
and(x,T) |
→ |
x |
(3) |
and(x,F) |
→ |
F |
(4) |
and(x,x) |
→ |
x |
(5) |
and(xor(x,y),z) |
→ |
xor(and(x,z),and(y,z)) |
(6) |
xor(x,x) |
→ |
F |
(7) |
impl(x,y) |
→ |
xor(and(x,y),xor(x,T)) |
(8) |
or(x,y) |
→ |
xor(and(x,y),xor(x,y)) |
(9) |
equiv(x,y) |
→ |
xor(x,xor(y,T)) |
(10) |
neg(x) |
→ |
xor(x,T) |
(11) |
Property / Task
Prove or disprove termination.Answer / Result
Yes.Proof (by AProVE @ termCOMP 2023)
1 Rule Removal
Using the
prec(xor) |
= |
0 |
|
stat(xor) |
= |
mul
|
prec(F) |
= |
0 |
|
stat(F) |
= |
mul
|
prec(neg) |
= |
1 |
|
stat(neg) |
= |
mul
|
prec(and) |
= |
2 |
|
stat(and) |
= |
mul
|
prec(T) |
= |
1 |
|
stat(T) |
= |
mul
|
prec(impl) |
= |
3 |
|
stat(impl) |
= |
mul
|
prec(or) |
= |
4 |
|
stat(or) |
= |
mul
|
prec(equiv) |
= |
5 |
|
stat(equiv) |
= |
mul
|
π(xor) |
= |
[1,2] |
π(F) |
= |
[] |
π(neg) |
= |
[1] |
π(and) |
= |
[1,2] |
π(T) |
= |
[] |
π(impl) |
= |
[1,2] |
π(or) |
= |
[1,2] |
π(equiv) |
= |
[1,2] |
all of the following rules can be deleted.
xor(x,F) |
→ |
x |
(1) |
xor(x,neg(x)) |
→ |
F |
(2) |
and(x,T) |
→ |
x |
(3) |
and(x,F) |
→ |
F |
(4) |
and(x,x) |
→ |
x |
(5) |
and(xor(x,y),z) |
→ |
xor(and(x,z),and(y,z)) |
(6) |
xor(x,x) |
→ |
F |
(7) |
impl(x,y) |
→ |
xor(and(x,y),xor(x,T)) |
(8) |
or(x,y) |
→ |
xor(and(x,y),xor(x,y)) |
(9) |
equiv(x,y) |
→ |
xor(x,xor(y,T)) |
(10) |
neg(x) |
→ |
xor(x,T) |
(11) |
1.1 R is empty
There are no rules in the TRS. Hence, it is terminating.