(0) Obligation:

Runtime Complexity TRS:
The TRS R consists of the following rules:

f(X) → f(c)
cb

Rewrite Strategy: INNERMOST

(1) InfiniteLowerBoundProof (EQUIVALENT transformation)

The loop following loop proves infinite runtime complexity:
The rewrite sequence
f(X) →+ f(c)
gives rise to a decreasing loop by considering the right hand sides subterm at position [].
The pumping substitution is [ ].
The result substitution is [X / c].

(2) BOUNDS(INF, INF)