Certification Problem

Input (TPDB TRS_Standard/Secret_05_TRS/cime2)

The rewrite relation of the following TRS is considered.

circ(cons(a,s),t) cons(msubst(a,t),circ(s,t)) (1)
circ(cons(lift,s),cons(a,t)) cons(a,circ(s,t)) (2)
circ(cons(lift,s),cons(lift,t)) cons(lift,circ(s,t)) (3)
circ(circ(s,t),u) circ(s,circ(t,u)) (4)
circ(s,id) s (5)
circ(id,s) s (6)
circ(cons(lift,s),circ(cons(lift,t),u)) circ(cons(lift,circ(s,t)),u) (7)
subst(a,id) a (8)
msubst(a,id) a (9)
msubst(msubst(a,s),t) msubst(a,circ(s,t)) (10)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by NaTT @ termCOMP 2023)

1 Dependency Pair Transformation

The following set of initial dependency pairs has been identified.
circ#(cons(lift,s),circ(cons(lift,t),u)) circ#(cons(lift,circ(s,t)),u) (11)
circ#(cons(lift,s),cons(lift,t)) circ#(s,t) (12)
circ#(circ(s,t),u) circ#(s,circ(t,u)) (13)
circ#(cons(a,s),t) msubst#(a,t) (14)
circ#(circ(s,t),u) circ#(t,u) (15)
msubst#(msubst(a,s),t) circ#(s,t) (16)
circ#(cons(lift,s),circ(cons(lift,t),u)) circ#(s,t) (17)
circ#(cons(lift,s),cons(a,t)) circ#(s,t) (18)
circ#(cons(a,s),t) circ#(s,t) (19)
msubst#(msubst(a,s),t) msubst#(a,circ(s,t)) (20)

1.1 Dependency Graph Processor

The dependency pairs are split into 1 component.