$($a$)$ Explain what is wrong with the given code. Describe the fault precisely by proposing a modification to the code.

$($b$)$ If possible, give a test case that does not execute the fault. If not, briefly explain why not.$$

$($c$)$ If possible, give a test case that executes the fault, but does not result in an error state. If not, briefly explain why not.

$($d$)$ If possible give a test case that results in an error, but not a failure. If not, briefly explain why not. Hint: Don$$t forget about the program counter.$$

$($e$)$ For the given test case, describe the first error state. Be sure to describe the complete state.