Term Rewriting System R:
[y, z, x]
f(cons(nil, y)) -> y
f(cons(f(cons(nil, y)), z)) -> copy(n, y, z)
copy(0, y, z) -> f(z)
copy(s(x), y, z) -> copy(x, y, cons(f(y), z))
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
f(cons(f(cons(nil, y)), z)) -> copy(n, y, z)
R
↳RRRI
→TRS2
↳Dependency Pair Analysis
R contains the following Dependency Pairs:
COPY(0, y, z) -> F(z)
COPY(s(x), y, z) -> COPY(x, y, cons(f(y), z))
COPY(s(x), y, z) -> F(y)
Furthermore, R contains one SCC.
R
↳RRRI
→TRS2
↳DPs
→DP Problem 1
↳Non-Overlappingness Check
Dependency Pair:
COPY(s(x), y, z) -> COPY(x, y, cons(f(y), z))
Rules:
f(cons(nil, y)) -> y
copy(0, y, z) -> f(z)
copy(s(x), y, z) -> copy(x, y, cons(f(y), z))
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
↳Usable Rules (Innermost)
Dependency Pair:
COPY(s(x), y, z) -> COPY(x, y, cons(f(y), z))
Rules:
f(cons(nil, y)) -> y
copy(0, y, z) -> f(z)
copy(s(x), y, z) -> copy(x, y, cons(f(y), z))
Strategy:
innermost
As we are in the innermost case, we can delete all 2 non-usable-rules.
R
↳RRRI
→TRS2
↳DPs
→DP Problem 1
↳NOC
...
→DP Problem 3
↳Size-Change Principle
Dependency Pair:
COPY(s(x), y, z) -> COPY(x, y, cons(f(y), z))
Rule:
f(cons(nil, y)) -> y
Strategy:
innermost
We number the DPs as follows:
- COPY(s(x), y, z) -> COPY(x, y, cons(f(y), z))
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:
cons(x1, x2) -> cons(x1, x2)
s(x1) -> s(x1)
We obtain no new DP problems.
Innermost Termination of R successfully shown.
Duration:
0:00 minutes