Termination Proof Script
Consider the TRS R consisting of the rewrite rules
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1: |
|
0(#) |
→ # |
2: |
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x + # |
→ x |
3: |
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# + x |
→ x |
4: |
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0(x) + 0(y) |
→ 0(x + y) |
5: |
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0(x) + 1(y) |
→ 1(x + y) |
6: |
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1(x) + 0(y) |
→ 1(x + y) |
7: |
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1(x) + 1(y) |
→ 0((x + y) + 1(#)) |
8: |
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(x + y) + z |
→ x + (y + z) |
9: |
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# * x |
→ # |
10: |
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0(x) * y |
→ 0(x * y) |
11: |
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1(x) * y |
→ 0(x * y) + y |
12: |
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(x * y) * z |
→ x * (y * z) |
13: |
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x * (y + z) |
→ (x * y) + (x * z) |
14: |
|
app(nil,l) |
→ l |
15: |
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app(cons(x,l1),l2) |
→ cons(x,app(l1,l2)) |
16: |
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sum(nil) |
→ 0(#) |
17: |
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sum(cons(x,l)) |
→ x + sum(l) |
18: |
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sum(app(l1,l2)) |
→ sum(l1) + sum(l2) |
19: |
|
prod(nil) |
→ 1(#) |
20: |
|
prod(cons(x,l)) |
→ x * prod(l) |
21: |
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prod(app(l1,l2)) |
→ prod(l1) * prod(l2) |
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There are 31 dependency pairs:
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22: |
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0(x) +# 0(y) |
→ 0#(x + y) |
23: |
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0(x) +# 0(y) |
→ x +# y |
24: |
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0(x) +# 1(y) |
→ x +# y |
25: |
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1(x) +# 0(y) |
→ x +# y |
26: |
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1(x) +# 1(y) |
→ 0#((x + y) + 1(#)) |
27: |
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1(x) +# 1(y) |
→ (x + y) +# 1(#) |
28: |
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1(x) +# 1(y) |
→ x +# y |
29: |
|
(x + y) +# z |
→ x +# (y + z) |
30: |
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(x + y) +# z |
→ y +# z |
31: |
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0(x) *# y |
→ 0#(x * y) |
32: |
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0(x) *# y |
→ x *# y |
33: |
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1(x) *# y |
→ 0(x * y) +# y |
34: |
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1(x) *# y |
→ 0#(x * y) |
35: |
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1(x) *# y |
→ x *# y |
36: |
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(x * y) *# z |
→ x *# (y * z) |
37: |
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(x * y) *# z |
→ y *# z |
38: |
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x *# (y + z) |
→ (x * y) +# (x * z) |
39: |
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x *# (y + z) |
→ x *# y |
40: |
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x *# (y + z) |
→ x *# z |
41: |
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APP(cons(x,l1),l2) |
→ APP(l1,l2) |
42: |
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SUM(nil) |
→ 0#(#) |
43: |
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SUM(cons(x,l)) |
→ x +# sum(l) |
44: |
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SUM(cons(x,l)) |
→ SUM(l) |
45: |
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SUM(app(l1,l2)) |
→ sum(l1) +# sum(l2) |
46: |
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SUM(app(l1,l2)) |
→ SUM(l1) |
47: |
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SUM(app(l1,l2)) |
→ SUM(l2) |
48: |
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PROD(cons(x,l)) |
→ x *# prod(l) |
49: |
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PROD(cons(x,l)) |
→ PROD(l) |
50: |
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PROD(app(l1,l2)) |
→ prod(l1) *# prod(l2) |
51: |
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PROD(app(l1,l2)) |
→ PROD(l1) |
52: |
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PROD(app(l1,l2)) |
→ PROD(l2) |
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The approximated dependency graph contains 5 SCCs:
{41},
{23-25,27-30},
{32,35-37,39,40},
{49,51,52}
and {44,46,47}.
-
Consider the SCC {41}.
There are no usable rules.
By taking the AF π with
π(APP) = 1
and π(cons) = [2] together with
the lexicographic path order with
empty precedence,
rule 41
is strictly decreasing.
-
Consider the SCC {23-25,27-30}.
The usable rules are {1-8}.
The constraints could not be solved.
-
Consider the SCC {32,35-37,39,40}.
The usable rules are {1-13}.
The constraints could not be solved.
-
Consider the SCC {49,51,52}.
There are no usable rules.
By taking the AF π with
π(PROD) = 1
and π(cons) = 2 together with
the lexicographic path order with
empty precedence,
rule 49
is weakly decreasing and
the rules in {51,52}
are strictly decreasing.
There is one new SCC.
-
Consider the SCC {49}.
By taking the AF π with
π(PROD) = 1
and π(cons) = [2] together with
the lexicographic path order with
empty precedence,
rule 49
is strictly decreasing.
-
Consider the SCC {44,46,47}.
There are no usable rules.
By taking the AF π with
π(SUM) = 1
and π(cons) = 2 together with
the lexicographic path order with
empty precedence,
rule 44
is weakly decreasing and
the rules in {46,47}
are strictly decreasing.
There is one new SCC.
-
Consider the SCC {44}.
By taking the AF π with
π(SUM) = 1
and π(cons) = [2] together with
the lexicographic path order with
empty precedence,
rule 44
is strictly decreasing.
Tyrolean Termination Tool (0.10 seconds)
--- May 4, 2006