Termination Proof Script

Consider the TRS R consisting of the rewrite rules
1:    active(first(0,X))  → mark(nil)
2:    active(first(s(X),cons(Y,Z)))  → mark(cons(Y,first(X,Z)))
3:    active(from(X))  → mark(cons(X,from(s(X))))
4:    active(first(X1,X2))  → first(active(X1),X2)
5:    active(first(X1,X2))  → first(X1,active(X2))
6:    active(s(X))  → s(active(X))
7:    active(cons(X1,X2))  → cons(active(X1),X2)
8:    active(from(X))  → from(active(X))
9:    first(mark(X1),X2)  → mark(first(X1,X2))
10:    first(X1,mark(X2))  → mark(first(X1,X2))
11:    s(mark(X))  → mark(s(X))
12:    cons(mark(X1),X2)  → mark(cons(X1,X2))
13:    from(mark(X))  → mark(from(X))
14:    proper(first(X1,X2))  → first(proper(X1),proper(X2))
15:    proper(0)  → ok(0)
16:    proper(nil)  → ok(nil)
17:    proper(s(X))  → s(proper(X))
18:    proper(cons(X1,X2))  → cons(proper(X1),proper(X2))
19:    proper(from(X))  → from(proper(X))
20:    first(ok(X1),ok(X2))  → ok(first(X1,X2))
21:    s(ok(X))  → ok(s(X))
22:    cons(ok(X1),ok(X2))  → ok(cons(X1,X2))
23:    from(ok(X))  → ok(from(X))
24:    top(mark(X))  → top(proper(X))
25:    top(ok(X))  → top(active(X))
There are 38 dependency pairs:
26:    ACTIVE(first(s(X),cons(Y,Z)))  → CONS(Y,first(X,Z))
27:    ACTIVE(first(s(X),cons(Y,Z)))  → FIRST(X,Z)
28:    ACTIVE(from(X))  → CONS(X,from(s(X)))
29:    ACTIVE(from(X))  → FROM(s(X))
30:    ACTIVE(from(X))  → S(X)
31:    ACTIVE(first(X1,X2))  → FIRST(active(X1),X2)
32:    ACTIVE(first(X1,X2))  → ACTIVE(X1)
33:    ACTIVE(first(X1,X2))  → FIRST(X1,active(X2))
34:    ACTIVE(first(X1,X2))  → ACTIVE(X2)
35:    ACTIVE(s(X))  → S(active(X))
36:    ACTIVE(s(X))  → ACTIVE(X)
37:    ACTIVE(cons(X1,X2))  → CONS(active(X1),X2)
38:    ACTIVE(cons(X1,X2))  → ACTIVE(X1)
39:    ACTIVE(from(X))  → FROM(active(X))
40:    ACTIVE(from(X))  → ACTIVE(X)
41:    FIRST(mark(X1),X2)  → FIRST(X1,X2)
42:    FIRST(X1,mark(X2))  → FIRST(X1,X2)
43:    S(mark(X))  → S(X)
44:    CONS(mark(X1),X2)  → CONS(X1,X2)
45:    FROM(mark(X))  → FROM(X)
46:    PROPER(first(X1,X2))  → FIRST(proper(X1),proper(X2))
47:    PROPER(first(X1,X2))  → PROPER(X1)
48:    PROPER(first(X1,X2))  → PROPER(X2)
49:    PROPER(s(X))  → S(proper(X))
50:    PROPER(s(X))  → PROPER(X)
51:    PROPER(cons(X1,X2))  → CONS(proper(X1),proper(X2))
52:    PROPER(cons(X1,X2))  → PROPER(X1)
53:    PROPER(cons(X1,X2))  → PROPER(X2)
54:    PROPER(from(X))  → FROM(proper(X))
55:    PROPER(from(X))  → PROPER(X)
56:    FIRST(ok(X1),ok(X2))  → FIRST(X1,X2)
57:    S(ok(X))  → S(X)
58:    CONS(ok(X1),ok(X2))  → CONS(X1,X2)
59:    FROM(ok(X))  → FROM(X)
60:    TOP(mark(X))  → TOP(proper(X))
61:    TOP(mark(X))  → PROPER(X)
62:    TOP(ok(X))  → TOP(active(X))
63:    TOP(ok(X))  → ACTIVE(X)
The approximated dependency graph contains 7 SCCs: {44,58}, {41,42,56}, {45,59}, {43,57}, {47,48,50,52,53,55}, {32,34,36,38,40} and {60,62}. Hence the TRS is terminating.
Tyrolean Termination Tool  (12.56 seconds)   ---  May 3, 2006