Term Rewriting System R:
[x]
not(true) -> false
not(false) -> true
evenodd(x, 0) -> not(evenodd(x, s(0)))
evenodd(0, s(0)) -> false
evenodd(s(x), s(0)) -> evenodd(x, 0)
Termination of R to be shown.
R
↳Removing Redundant Rules
Removing the following rules from R which fullfill a polynomial ordering:
evenodd(0, s(0)) -> false
where the Polynomial interpretation:
POL(0) | = 0 |
POL(evenodd(x1, x2)) | = 1 + x1 + x2 |
POL(false) | = 0 |
POL(true) | = 0 |
POL(s(x1)) | = x1 |
POL(not(x1)) | = x1 |
was used.
Not all Rules of R can be deleted, so we still have to regard a part of R.
R
↳RRRPolo
→TRS2
↳Overlay and local confluence Check
The TRS is overlay and locally confluent (all critical pairs are trivially joinable).Hence, we can switch to innermost.
R
↳RRRPolo
→TRS2
↳OC
→TRS3
↳Dependency Pair Analysis
R contains the following Dependency Pairs:
EVENODD(s(x), s(0)) -> EVENODD(x, 0)
EVENODD(x, 0) -> NOT(evenodd(x, s(0)))
EVENODD(x, 0) -> EVENODD(x, s(0))
Furthermore, R contains one SCC.
R
↳RRRPolo
→TRS2
↳OC
→TRS3
↳DPs
...
→DP Problem 1
↳Usable Rules (Innermost)
Dependency Pairs:
EVENODD(x, 0) -> EVENODD(x, s(0))
EVENODD(s(x), s(0)) -> EVENODD(x, 0)
Rules:
evenodd(s(x), s(0)) -> evenodd(x, 0)
evenodd(x, 0) -> not(evenodd(x, s(0)))
not(true) -> false
not(false) -> true
Strategy:
innermost
As we are in the innermost case, we can delete all 4 non-usable-rules.
R
↳RRRPolo
→TRS2
↳OC
→TRS3
↳DPs
...
→DP Problem 2
↳Size-Change Principle
Dependency Pairs:
EVENODD(x, 0) -> EVENODD(x, s(0))
EVENODD(s(x), s(0)) -> EVENODD(x, 0)
Rule:
none
Strategy:
innermost
We number the DPs as follows:
- EVENODD(x, 0) -> EVENODD(x, s(0))
- EVENODD(s(x), s(0)) -> EVENODD(x, 0)
and get the following Size-Change Graph(s):
which lead(s) to this/these maximal multigraph(s):
DP: empty set
Oriented Rules: none
We used the order Homeomorphic Embedding Order with Non-Strict Precedence.
trivial
with Argument Filtering System:
s(x1) -> s(x1)
We obtain no new DP problems.
Termination of R successfully shown.
Duration:
0:00 minutes