### (0) Obligation:

Runtime Complexity TRS:

The TRS R consists of the following rules:

f(a, X) → f(X, X)

c → a

c → b

Rewrite Strategy: FULL

### (1) InfiniteLowerBoundProof (EQUIVALENT transformation)

The loop following loop proves infinite runtime complexity:

The rewrite sequence

f(a, a) →^{+} f(a, a)

gives rise to a decreasing loop by considering the right hand sides subterm at position [].

The pumping substitution is [ ].

The result substitution is [ ].

### (2) BOUNDS(INF, INF)