Removing Useless Variables in Cost Analysis of Java Bytecode

Automatic cost analysis has interesting applications in the context of verification and certification of mobile code. For instance, the code receiver can use cost information in order to decide whether to reject mobile code which has too large cost requirements in terms of computing resources (in time and/or space) or billable events (SMSs sent, bandwidth re-quired). Existing cost analyses for a variety of languages describe the resource consumption of programs by means of Cost Equation Systems (CESs), which are similar to, but more general than recurrence equations. CESs express the cost of a program in terms of the size of its input data. In a further step, a closed form (i.e., non-recursive) solu-tion or upper bound can sometimes be found by using ex-isting Computer Algebra Systems (CASs), such as Mapl