Certification Problem

Input (TPDB TRS_Standard/Transformed_CSR_04/Ex26_Luc03b_C)

The rewrite relation of the following TRS is considered.

active(terms(N)) mark(cons(recip(sqr(N)),terms(s(N)))) (1)
active(sqr(0)) mark(0) (2)
active(sqr(s(X))) mark(s(add(sqr(X),dbl(X)))) (3)
active(dbl(0)) mark(0) (4)
active(dbl(s(X))) mark(s(s(dbl(X)))) (5)
active(add(0,X)) mark(X) (6)
active(add(s(X),Y)) mark(s(add(X,Y))) (7)
active(first(0,X)) mark(nil) (8)
active(first(s(X),cons(Y,Z))) mark(cons(Y,first(X,Z))) (9)
active(terms(X)) terms(active(X)) (10)
active(cons(X1,X2)) cons(active(X1),X2) (11)
active(recip(X)) recip(active(X)) (12)
active(sqr(X)) sqr(active(X)) (13)
active(add(X1,X2)) add(active(X1),X2) (14)
active(add(X1,X2)) add(X1,active(X2)) (15)
active(dbl(X)) dbl(active(X)) (16)
active(first(X1,X2)) first(active(X1),X2) (17)
active(first(X1,X2)) first(X1,active(X2)) (18)
terms(mark(X)) mark(terms(X)) (19)
cons(mark(X1),X2) mark(cons(X1,X2)) (20)
recip(mark(X)) mark(recip(X)) (21)
sqr(mark(X)) mark(sqr(X)) (22)
add(mark(X1),X2) mark(add(X1,X2)) (23)
add(X1,mark(X2)) mark(add(X1,X2)) (24)
dbl(mark(X)) mark(dbl(X)) (25)
first(mark(X1),X2) mark(first(X1,X2)) (26)
first(X1,mark(X2)) mark(first(X1,X2)) (27)
proper(terms(X)) terms(proper(X)) (28)
proper(cons(X1,X2)) cons(proper(X1),proper(X2)) (29)
proper(recip(X)) recip(proper(X)) (30)
proper(sqr(X)) sqr(proper(X)) (31)
proper(s(X)) s(proper(X)) (32)
proper(0) ok(0) (33)
proper(add(X1,X2)) add(proper(X1),proper(X2)) (34)
proper(dbl(X)) dbl(proper(X)) (35)
proper(first(X1,X2)) first(proper(X1),proper(X2)) (36)
proper(nil) ok(nil) (37)
terms(ok(X)) ok(terms(X)) (38)
cons(ok(X1),ok(X2)) ok(cons(X1,X2)) (39)
recip(ok(X)) ok(recip(X)) (40)
sqr(ok(X)) ok(sqr(X)) (41)
s(ok(X)) ok(s(X)) (42)
add(ok(X1),ok(X2)) ok(add(X1,X2)) (43)
dbl(ok(X)) ok(dbl(X)) (44)
first(ok(X1),ok(X2)) ok(first(X1,X2)) (45)
top(mark(X)) top(proper(X)) (46)
top(ok(X)) top(active(X)) (47)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Dependency Pair Transformation

The following set of initial dependency pairs has been identified.
active#(terms(N)) cons#(recip(sqr(N)),terms(s(N))) (48)
active#(terms(N)) recip#(sqr(N)) (49)
active#(terms(N)) sqr#(N) (50)
active#(terms(N)) terms#(s(N)) (51)
active#(terms(N)) s#(N) (52)
active#(sqr(s(X))) s#(add(sqr(X),dbl(X))) (53)
active#(sqr(s(X))) add#(sqr(X),dbl(X)) (54)
active#(sqr(s(X))) sqr#(X) (55)
active#(sqr(s(X))) dbl#(X) (56)
active#(dbl(s(X))) s#(s(dbl(X))) (57)
active#(dbl(s(X))) s#(dbl(X)) (58)
active#(dbl(s(X))) dbl#(X) (59)
active#(add(s(X),Y)) s#(add(X,Y)) (60)
active#(add(s(X),Y)) add#(X,Y) (61)
active#(first(s(X),cons(Y,Z))) cons#(Y,first(X,Z)) (62)
active#(first(s(X),cons(Y,Z))) first#(X,Z) (63)
active#(terms(X)) terms#(active(X)) (64)
active#(terms(X)) active#(X) (65)
active#(cons(X1,X2)) cons#(active(X1),X2) (66)
active#(cons(X1,X2)) active#(X1) (67)
active#(recip(X)) recip#(active(X)) (68)
active#(recip(X)) active#(X) (69)
active#(sqr(X)) sqr#(active(X)) (70)
active#(sqr(X)) active#(X) (71)
active#(add(X1,X2)) add#(active(X1),X2) (72)
active#(add(X1,X2)) active#(X1) (73)
active#(add(X1,X2)) add#(X1,active(X2)) (74)
active#(add(X1,X2)) active#(X2) (75)
active#(dbl(X)) dbl#(active(X)) (76)
active#(dbl(X)) active#(X) (77)
active#(first(X1,X2)) first#(active(X1),X2) (78)
active#(first(X1,X2)) active#(X1) (79)
active#(first(X1,X2)) first#(X1,active(X2)) (80)
active#(first(X1,X2)) active#(X2) (81)
terms#(mark(X)) terms#(X) (82)
cons#(mark(X1),X2) cons#(X1,X2) (83)
recip#(mark(X)) recip#(X) (84)
sqr#(mark(X)) sqr#(X) (85)
add#(mark(X1),X2) add#(X1,X2) (86)
add#(X1,mark(X2)) add#(X1,X2) (87)
dbl#(mark(X)) dbl#(X) (88)
first#(mark(X1),X2) first#(X1,X2) (89)
first#(X1,mark(X2)) first#(X1,X2) (90)
proper#(terms(X)) terms#(proper(X)) (91)
proper#(terms(X)) proper#(X) (92)
proper#(cons(X1,X2)) cons#(proper(X1),proper(X2)) (93)
proper#(cons(X1,X2)) proper#(X1) (94)
proper#(cons(X1,X2)) proper#(X2) (95)
proper#(recip(X)) recip#(proper(X)) (96)
proper#(recip(X)) proper#(X) (97)
proper#(sqr(X)) sqr#(proper(X)) (98)
proper#(sqr(X)) proper#(X) (99)
proper#(s(X)) s#(proper(X)) (100)
proper#(s(X)) proper#(X) (101)
proper#(add(X1,X2)) add#(proper(X1),proper(X2)) (102)
proper#(add(X1,X2)) proper#(X1) (103)
proper#(add(X1,X2)) proper#(X2) (104)
proper#(dbl(X)) dbl#(proper(X)) (105)
proper#(dbl(X)) proper#(X) (106)
proper#(first(X1,X2)) first#(proper(X1),proper(X2)) (107)
proper#(first(X1,X2)) proper#(X1) (108)
proper#(first(X1,X2)) proper#(X2) (109)
terms#(ok(X)) terms#(X) (110)
cons#(ok(X1),ok(X2)) cons#(X1,X2) (111)
recip#(ok(X)) recip#(X) (112)
sqr#(ok(X)) sqr#(X) (113)
s#(ok(X)) s#(X) (114)
add#(ok(X1),ok(X2)) add#(X1,X2) (115)
dbl#(ok(X)) dbl#(X) (116)
first#(ok(X1),ok(X2)) first#(X1,X2) (117)
top#(mark(X)) top#(proper(X)) (118)
top#(mark(X)) proper#(X) (119)
top#(ok(X)) top#(active(X)) (120)
top#(ok(X)) active#(X) (121)

1.1 Dependency Graph Processor

The dependency pairs are split into 11 components.