Term Rewriting System R:
[x, y, z]
times(x, plus(y, s(z))) -> plus(times(x, plus(y, times(s(z), 0))), times(x, s(z)))
times(x, 0) -> 0
times(x, s(y)) -> plus(times(x, y), x)
plus(x, 0) -> x
plus(x, s(y)) -> s(plus(x, y))
Innermost Termination of R to be shown.
R
↳Removing Redundant Rules for Innermost Termination
Removing the following rules from R which left hand sides contain non normal subterms
times(x, plus(y, s(z))) -> plus(times(x, plus(y, times(s(z), 0))), times(x, s(z)))
R
↳RRRI
→TRS2
↳Dependency Pair Analysis
R contains the following Dependency Pairs:
TIMES(x, s(y)) -> PLUS(times(x, y), x)
TIMES(x, s(y)) -> TIMES(x, y)
PLUS(x, s(y)) -> PLUS(x, y)
Furthermore, R contains two SCCs.
R
↳RRRI
→TRS2
↳DPs
→DP Problem 1
↳Non-Overlappingness Check
→DP Problem 2
↳NOC
Dependency Pair:
PLUS(x, s(y)) -> PLUS(x, y)
Rules:
times(x, 0) -> 0
times(x, s(y)) -> plus(times(x, y), x)
plus(x, 0) -> x
plus(x, s(y)) -> s(plus(x, y))
R does not overlap into P. Moreover, R is locally confluent (all critical pairs are trivially joinable).Hence we can switch to innermost.
The transformation is resulting in one subcycle:
R
↳RRRI
→TRS2
↳DPs
→DP Problem 1
↳NOC
...
→DP Problem 3
↳Usable Rules (Innermost)
→DP Problem 2
↳NOC
Dependency Pair:
PLUS(x, s(y)) -> PLUS(x, y)
Rules:
times(x, 0) -> 0
times(x, s(y)) -> plus(times(x, y), x)
plus(x, 0) -> x
plus(x, s(y)) -> s(plus(x, y))
Strategy:
innermost
As we are in the innermost case, we can delete all 4 non-usable-rules.
R
↳RRRI
→TRS2
↳DPs
→DP Problem 1
↳NOC
...
→DP Problem 4
↳Size-Change Principle
→DP Problem 2
↳NOC
Dependency Pair:
PLUS(x, s(y)) -> PLUS(x, y)
Rule:
none
Strategy:
innermost
We number the DPs as follows:
- PLUS(x, s(y)) -> PLUS(x, y)
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.
R
↳RRRI
→TRS2
↳DPs
→DP Problem 1
↳NOC
→DP Problem 2
↳Non-Overlappingness Check
Dependency Pair:
TIMES(x, s(y)) -> TIMES(x, y)
Rules:
times(x, 0) -> 0
times(x, s(y)) -> plus(times(x, y), x)
plus(x, 0) -> x
plus(x, s(y)) -> s(plus(x, y))
R does not overlap into P. Moreover, R is locally confluent (all critical pairs are trivially joinable).Hence we can switch to innermost.
The transformation is resulting in one subcycle:
R
↳RRRI
→TRS2
↳DPs
→DP Problem 1
↳NOC
→DP Problem 2
↳NOC
...
→DP Problem 5
↳Usable Rules (Innermost)
Dependency Pair:
TIMES(x, s(y)) -> TIMES(x, y)
Rules:
times(x, 0) -> 0
times(x, s(y)) -> plus(times(x, y), x)
plus(x, 0) -> x
plus(x, s(y)) -> s(plus(x, y))
Strategy:
innermost
As we are in the innermost case, we can delete all 4 non-usable-rules.
R
↳RRRI
→TRS2
↳DPs
→DP Problem 1
↳NOC
→DP Problem 2
↳NOC
...
→DP Problem 6
↳Size-Change Principle
Dependency Pair:
TIMES(x, s(y)) -> TIMES(x, y)
Rule:
none
Strategy:
innermost
We number the DPs as follows:
- TIMES(x, s(y)) -> TIMES(x, y)
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.
Innermost Termination of R successfully shown.
Duration:
0:00 minutes