(0) Obligation:

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

f(a) → f(c(a))
f(c(X)) → X
f(c(a)) → f(d(b))
f(a) → f(d(a))
f(d(X)) → X
f(c(b)) → f(d(a))
e(g(X)) → e(X)

Rewrite Strategy: FULL

(1) DecreasingLoopProof (EQUIVALENT transformation)

The following loop(s) give(s) rise to the lower bound Ω(n1):
The rewrite sequence
e(g(X)) →+ e(X)
gives rise to a decreasing loop by considering the right hand sides subterm at position [].
The pumping substitution is [X / g(X)].
The result substitution is [ ].

(2) BOUNDS(n^1, INF)