[A.I] Give a complete problem formulation for the following problem. Choose a formulation that is precise enough to be implemented: You start with the sequence ABABAECCEC, or in general any sequence made from A, B, C, and E. You can transform this sequence using the following equalities: AC=E, AB=BC, BB=E, and Ex=x for any x. For example, ABBC can be transformed into AEC, and then AC, and then E. Your goal is to produce the sequence E.