Termination of the following Term Rewriting System could be proven:

Context-sensitive rewrite system:
The TRS R consists of the following rules:

f(f(a)) → f(g(f(a)))

The replacement map contains the following entries:

f: {1}
a: empty set
g: empty set


CSR
  ↳ CSRInnermostProof

Context-sensitive rewrite system:
The TRS R consists of the following rules:

f(f(a)) → f(g(f(a)))

The replacement map contains the following entries:

f: {1}
a: empty set
g: empty set

The CSR is orthogonal. By [10] we can switch to innermost.

↳ CSR
  ↳ CSRInnermostProof
CSR
      ↳ CSDependencyPairsProof

Context-sensitive rewrite system:
The TRS R consists of the following rules:

f(f(a)) → f(g(f(a)))

The replacement map contains the following entries:

f: {1}
a: empty set
g: empty set

Innermost Strategy.

Using Improved CS-DPs we result in the following initial Q-CSDP problem.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
QCSDP
          ↳ QCSDependencyGraphProof

Q-restricted context-sensitive dependency pair problem:
The symbols in {f, F} are replacing on all positions.
The symbols in {g} are not replacing on any position.

The ordinary context-sensitive dependency pairs DPo are:

F(f(a)) → F(g(f(a)))

The TRS R consists of the following rules:

f(f(a)) → f(g(f(a)))

The set Q consists of the following terms:

f(f(a))


The approximation of the Context-Sensitive Dependency Graph contains 0 SCCs.
The rules F(f(a)) → F(g(f(a))) and F(f(a)) → F(g(f(a))) form no chain, because ECapµ(F(g(f(a)))) = F(g(f(a))) does not unify with F(f(a)).